Nutrition 313 Exam 3 [Final]

Recall the tissue (body) composition of the healthy, full term new born

A healthy full-term baby is born between 38-40 weeks' gestation; weighs between 3-4 kilograms; is pink all over at birth and 5 minutes afterward; has a sustained heart rate of 100 beats per minute or more; and promptly demonstrates deep and regular crying. Early consumption of sufficient amounts of enzyme cofactors folate, B12, and B6 greatly enhances fetal outcomes that depend on methylation reactions during embryonic and fetal development stages. Methylation reaction outcomes in early pregnancy include gene expression, cell division and synthesis of DNA (nucleic acid) which are all needed for differentiation of the central nervous system.

Recall nutrient intake guidelines for disease prevention and therapy(Focus on nutrients with higher/ lower daily quantities to control blood lipids, glycemic and inflammatory responses, and blood pressure)

A person's riskof developing certain metabolic diseases is influenced by a variety of factors. Most of these factors are outside of our control, as they relate to the natural aging processes, sex hormones or familial factors involving race and ethnicity. Hereditary or in utero gene defects are also largely out of human control but, advancing technology allows scientists to predict the likelihood of these risk factors with an increasing level of accuracy. The manageable disease risk factors, known as "lifestyle factors" include inactivity, smoking, mental stress, and poor diet. These factors can have a decisive impact on promoting the onset and progression of diseases and, when controlled, partially mitigate disease risk and re-occurrence. Excess calorieintake and ensuing excess body fat weight (i.e., obesity) is directly linked to higher risk of developing cancer, cardiovascular disease and type II diabetes. Coupling calorie restrictionsfrom balanced amounts of essential nutrients with appropriate levels of physical activity usually elicit healthy weight loss, yielding a 500-1,000 calorie deficit each day. Nutrition for weight loss will be discussed in more detail in Chapter 11. The unique fatty acid profile of the typical American diet may play an important role in the etiology of chronic diseases in the US. To improve that profile, the guidelines for recommended fats have been modeled after the guiding principles of the Mediterranean diet, with some inspiration from other long-living populations such as some groups of Eskimos and Japanese adults. Mediterranean diets permit the consumption of 20-30%of total calories from fat, with most being of the monounsaturated and essential, polyunsaturated-type. This diet pattern is low in non-essential polyunsaturated fatty acids and is even lower in saturated fats. Since the American diet is high in saturated fats, the American Heart Association's National Cholesterol Education Program (NCEP) recommends limiting saturated fats substantially to 7% or less of total calories, and trans fats to less than 1%. For the small number of people who are "hyper-responders" to dietary cholesterol, exogenous cholesterol intake should be limited to less than 200 mg/day. However, for the majority of healthy adults, daily cholesterol intake does not significantly affect blood cholesterol and should be restricted to the typical level of around 300 mg/day. While the consumption of carbohydratesin the form of corn syrup in the typical American has grown, and the intake of dietary fiber has declined, the prevalence of type 2 diabetes has escalated. Carbohydrate intake for disease therapy and prevention should aim to provide roughly 50-60% of calories from mainly complex carbohydrates, and restricted to less than 10% from added sugars. Although current US dietary guidelines do not use glycemic index (GI) nor glycemic load (GL) measurements, diets with lower GI or GL levels that are higher in dietary fiber from whole plant foods, rich in viscous fiber are recommended for diabetes prevention and treatment. For individuals diagnosed with diabetes, 25-50 g fiber/day with a good portion from viscous fiber sources is beneficial for reducing disease-associated risks. Sodium-rich diets can lead to hypertension in healthy people, in people who are "salt sensitive," or in those who already exhibit pre-hypertensive symptoms. A low sodium diet has been an effective way to reduce blood pressure. The Dietary Approaches to Stop Hypertension (DASH) diet recommends daily consumption of no more than 1500 mg of sodium chloride(i.e., salt) together with a concomitant increase in potassium-rich food intake. Since cell stress is exacerbated in the presence of free radicals, and exogenous antioxidants from the diet mitigate cell damage associated with atherosclerosis and cancer development, antioxidant intakeis an important dietary consideration for those concerned with disease prevention. While there are many unsubstantiated claims about the benefits of antioxidant nutrients, there is reliable scientific evidence for some vitamins including beta carotene, vitamin C and tocopherol that may, indeed, have protective benefits. A number of phytochemical compoundsmay additionally contribute to the disease protective-effects of plant foods. And while phytochemicals are not established essential nutrients, they have been evaluated in nutrition research for their ability to reduce oxidative damage, pro-inflammatory gene transcription and cholesterol absorption. And although supplementation of individual micronutrients or phytochemicals from superfoods has not generally resulted in significantly decreased incidence of disease morbidities, the potential of whole foods rich in these compounds cannot be overlooked.

Identify factors related to dysfunctional nutrient processing in the epithelium

A prominent feature of endothelial dysfunctionis diminished vascular enzyme nitric oxide synthase, or eNOS, activity. "Uncoupled" eNOS leads to superoxide radical formation, which rapidly reacts with nitric oxide to form peroxynitrite anion. This reaction initiates a pro-inflammatory responsein the endothelium, which impairs Akt kinase phosphorylation. The combined effects of inadequate dilation of blood vessels to dispose of glucose and reduced glucose uptake due to failed Akt kinase activation and translocation of GLUT-4 in the muscle, produce hyperglycemia. Following a high salt meal, or with chronic high salt intake, plasma sodium levels increase from the normal values to 135-150 mmol/L. Increased plasma sodium, coupled with limited dilation capacity caused by endothelial dysfunction in the small vessels of the kidney, causes increased fluid retention. This additional fluid causes pressure and stiffness within the endothelium and between the smooth muscle layer leading to high blood pressure. High blood pressure leads to pre-hypertension (120/80 mm/Hg) and, eventually if untreated, hypertension (140/90 mmHg). Hypertension is a clinical condition that promotes inflammatory response and enhances LDL and platelet aggregation and plaque formation. Chronic excess intake of saturated and polyunsaturated fatscontributes to endothelial dysfunction. Endothelial cell membranes are composed of glycolipids and phospholipids that feature 16-20 carbon chains with, or without, double bonds. The length and degree of unsaturation of these carbon chains have a profound effect on membrane fluidity as unsaturated lipids create a kink, preventing the fatty acids from packing together as tightly, thereby increasing membrane fluidity. A lipid bilayer with many double bonds though is more susceptible to free radical oxidation and ensuing inflammation. Excessive and prolonged intake of polyunsaturated fats in combination with high glycemic foods exacerbates endothelial dysfunction. Endothelial cell membranes serve as a pool of polyunsaturated fatty acids that can be converted to various bioactive lipids for metabolism. Insulin and other cell signalers initiate enzymes to cleave fatty acids from the sn-2 position of membrane phospholipids. Liberated fatty acids serve as substrates for the production of bioactive lipid mediators, DGLA, di-homo-y-linolenic acid, arachidonic acid (AA) and eicosapentaenoic acid (EPA). Insulincatalyzes desaturase enzymes to direct linoleic acid through the pathway to the pro-inflammatory eicosanoid AA, instead of the anti-inflammatory eicosanoid, EPA. AA triggers the release of inflammatory cytokines that cause platelet aggregation, which initiates clotting and vasoconstriction of the endothelial smooth muscle. Platelet aggregationis a harmful first step in the formation of blood clots that can occlude arteries and lead to myocardial infarction, or ischemic stroke.

Explain the impact ofgrowing and aging on daily nutrient requirements

A young infantneeds two to four times the dailyenergy per unit of body weight, as compared to adults (40-50 calories/kg/day). The additional energy supports accelerated rates of tissue building and helps to maintain a 98.6º F core body temperature with a relatively high body surface area-to-weight ratio. Daily energy intake for the average size, healthy, four to six-month-old infant is anywhere from 500-600 calories per day, which is consistent with the average amount secreted daily in human breast milk. Carbohydrates in breast milk are also adequate to sustain the daily glucose needs of the brain and central nervous system, which are estimated to use around 17 grams of carbohydrates per day. Fat and cholesterol in breast milk are also adequate, support neural development, and produce tremendous gains in body fat mass over the first six-month period. Protein requirementsof infants, per unit of body weight, are 75% higher than those of adults and are estimated to average 1.52 grams/kg/day. To prevent infants from bleeding out in the case of an injury, a 0.5-1 mg intramuscular vitamin Kprophylaxis is given at birth to hold over the infant until the intestinal microflora that produces vitamin K mature and the clotting function is adequate. Another good example is Vitamin D — Vitamin Dlevels are naturally low in breast milk so pediatricians may advise a liquid vitamin D supplementfor exclusively breast-fed infants who are not regularly exposed to small daily doses of UV light, especially if maternal vitamin D intake is low. Young infants with vegan mothers may similarly need special attention when it comes to vitamin B12, as they may be born with lower storage endowments and have a persistently low-level milk supply that mirrors the maternal diet. The daily requirements of older infants, in the range ofseven to twelve months old, are based on a slightly lower intake of .6 liters of breast milk per day added to amounts from 400 calories of complementary weaning foods. For many nutrients, data related to content and volume of weaning food intake is not available. Accordingly, the daily requirements were extrapolated from the adequate intake of healthy 0 to 6-month-old infants, and healthy adults by adjusting for body weight and metabolic rate. Around six months after birth, it is likely that iron stores endowed at birth have been fully utilized. Since the iron in breast milk at this point is also relatively low, iron needs must be met "exogenously," or by diet sources. Dailyironrequirementsfor older infants are estimated using a factorial model that weighs the amount of iron deposited in the expansion of hemoglobin mass and blood volume, the amount deposited in storage and iron-containing tissues, and daily fecal, urinary and dermal losses. Like iron, newborn birth stores of zinc progressively decline across the first six months, coinciding with a reduction in the concentration in breast milk. Dietaryzinc requirementsfrom six months of age onward are determined using a factorial approach similar to the method used for iron, where the sum of zinc tissue deposition and basal zinc losses are corrected by the bioavailability of zinc in the diet. Daily protein requirementsfor older infants are also estimated using factorial methods that add together the protein needed for protein turnover, or "maintenance," and the amount deposited in new tissue mass, corrected by a score for the efficiency of protein utilization. At every stage of life after the age of one, 14 grams offiberper 1000 calories is recommended. Protein requirementsfor young children, much like every older stage of life, are determined using the factorial model described above for older infants, with a slightly lower protein deposition factor since the rate of growth is lower relative to total body mass. Iron andZinc needs for toddlers and all older people are also determined using the same factorial model but with adjustments for slowed hemoglobin mass expansion and reduced rates of tissue growth. Daily vitamin Drequirements for toddlers aged one to three years are based on downward extrapolations from older children (ages four to eight) living in different continents where exposure to sunlight is variable. Serum vitamin D is the primary indicator of daily vitamin D requirement, as it correlates well with cumulative exposure to sunlight and dietary intake of vitamin D. If sun exposure is consistently adequate throughout the year, most children with typical dietary intake are not at risk of vitamin D deficiency. Since vitamin D is limited in the natural food supply, though, children of all ages that use UV protective sunscreens should consider adding 15-20 μg of vitamin D-fortified food products or supplements to their diets. For four to eight-year-olds, nutrient demands are not what they were during toddlerhood. There is a slower rate of the nutrient deposition so that children in this group are at a lower risk of protein, iron and zinc deficiency compared to both younger and older children. However, it is not uncommon for children in this age range to refuse certain foods and resist the mixing or touching of meal components. To mitigate these psychological difficulties, it is recommended that children in this age group be allowed to participate in food shopping and meal preparation as it can also strengthen their sense of task completion, partnership, artistry, and self-confidence. Typically, by age five, children are influenced by external factors that can override their internal hunger and satiety signals; when coupled with a preference for sweet and salty tastes,excess calorie consumption can become problematic. The number of children who are overweight or obese in this age group has more than tripled in the last 20 years, due, at least in part, to the fact that around half of them now drink soda regularly and nearly all of them eat at least one meal away from home daily. It might come as little surprise, then, that most children ages 4-8 living in the US recognize the most popular fast food and junk food brands. The period of adolescence spans from 9 to 18 years old and is divided into two periods that span 9-13 and 14-18 years of age. The 9 to 13-year-old span is called "puberty," and those 14 years and old are known as "teens." Both periods are associated with great gains in body mass and stature as well as reproductive developments that are the beginning of the physical transformation from childhood to adulthood. The protein needsof adolescents are influenced by the amount of protein required for maintenance of existing lean body mass and accrual of additional lean body mass during the adolescent growth spurt. Protein requirements per unit of height are highest for females in the 11 to 14-year age range and for males in the 15 to 18-year age range, corresponding to the usual timing of each gender's peak height velocity. In the US, adolescents consume nearly two times more than adequate amounts of protein. Conversely, subgroups of adolescents who may be at risk for low protein intakes include those from food-insecure households, those who severely restrict calories, and vegans. Early teens typically gain independence in managing where they spend their time, and with that comes the freedom to choose what foods they eat. Often, teens congregate for social activities at food establishments, including fast-food restaurants where soft drinks, and high fat, fried and salted foods predominate. As a result, the adolescent eating pattern, especially the one observed in teens, is problematic because nutrients that should be kept limited in the diet are often over-consumed. For instance, nearly 15% of the total carbohydrates consumed by adolescents come from corn syrup and sucrose additives alone, which ranges from nearly 1/2 cup for females ages 9-18 to 3/4 cup for males ages 14-18 each day. Over 30% of 12 to19-year-olds also exceed the guideline for calories from fat and saturated fat, as well as sodium intake which in boys specifically, is almost double the adult salt intake target (4474 mg/day). In addition, cholesterol intake exceeds guidelines for nearly a quarter of teens, and a higher proportion does not meet the daily amounts of fiber associated with good health. Teenagers are busy. As a result, as with adults, meals are skipped and sit-down meals are sometimes replaced with grazingand snacking. Snacking and grazing foods are typically more shelf-stable (i.e., more additives), less nutritious, and offer less nutrient variety than prepared meals. As a result, teenagers may consume inadequate amounts of nutrients needed for long-term good health. One of the key nutrients teenagers may miss is dietary calcium. Studies indicate that nearly a quarter of teenage girls fall short of the daily target for calcium intake, a shortfall compounded by the fact that both boys and girls in this age group begin to consume more than acceptable levels of salt and caffeine from soda, both of which contribute to calcium losses. Teens who substitute soda for milk and fortified fruit juice and consume lower than recommended amounts of fruits and vegetables can also fail to meet their daily intake needs of vitamins C, E and A. These latter two vitamins and dietary folate especially must be adequate during the growth spurt to accommodate DNA, RNA, and protein synthesis. Iron requirements for teenagers are based on the factorial modeling approach described above for younger children. For both male and female teens, the need for iron increases with rapid growth and the expansion of blood volume and muscle mass, which is highest during the adolescent growth spurt in males and after menarche in females. Like iron, zinc requirementsfor teens are estimated using the factorial approach described above for other children, except that the amount of zinc required for new tissue accretion is higher; zinc losses, extrapolated from adult data, also include menstrual and semen losses and a slightly higher fractional zinc absorption coefficient. Like calcium, and several other mineral nutrients, zinc is not obtained in sufficient amounts in a quarter of teen girls, and for that reason, supplementing these minerals may be warranted. Around the fifth decade, depending on the interaction of genetic and environmental factors, there is a gradual shift in tissue turnover so that tissue synthesis is outpaced by tissue breakdown. However, since most people in older adulthood, aged 51-70 years, are still actively working, the physiological indicators and daily intake levels for most nutrients in the DRI for this age range are the same as healthy adults, aged 19 to 50 years, as discussed in Chapters 2-7. The nutrient requirements for men and women over 70 years are also primarily extrapolated from healthy adults 19-50 years old, and modeled with data using subjects aged anywhere from 51+ and up since there is as much as a 15 to 20-year age-related difference in the level of reserve and functional capacity between elderly individuals in the 71+ age group. Calorie and proteinrequirements for older and elderly adults are determined using the same formulas and models as healthy children and non-pregnant adults. The formula for the estimated energy requirement (EER) is adjusted for aging by including coefficients for age, weight and physical activity level, which accounts for some of the major variances in daily energy expenditures. The EER formula does not, however, account for changing body composition, which also significantly affects the metabolic rate. Anywhere between 40-50, usually younger for men, there are age-related reductions in all three components of EE, that collectively reduce the TDEE by approximately 1-2% per decade. This rate of decline is usually more dramatic after the age of 60 until basal metabolism or energy requirements are diminished by about 100 kcal/day per decade. Micronutrient needs also deserve attention in elderly nutrition. For instance, B12 requirements, while not different than younger adults, are followed with a guideline that B12-fortified foods (such as fortified ready-to-eat cereals) or B12-containing supplements made with crystalline B12 should meet a large portion of the total daily B12 requirement. Because these synthetic B12 forms are more absorbable than the protein-bound type in food, and because 10-30% of the people older than 50 years have atrophic gastritis coupled with low stomach acid secretion, which further inhibits protein and B12 dissociation and absorption, anyone over 50 should consider foods that have added B12totaling the 2.4 microgram requirement. The relationship between functional losses and dietary inadequacies are more apparent for several nutrients in adults older than 51 years of age. As a result, their intake levels must be increased. The additional target for vitamin B6 offsets the natural blood homocysteine increases that occur even when folate and vitamin B12 status are adequate. For calcium, there is an additional 200 mg per day added to the 1000 mg adult AI for elderly adults over 71 years old. To minimize bone loss, older men (>70 years) and postmenopausal women should consume a dietary supplement that satisfies at least 25% of the calcium RDA. Since the DRI for calcium assumes that the requirement for vitamin Dis being met, the use of a combined calcium and vitamin D supplement in the prevention of osteoporosis in older adults is common. The elderly are often at a higher risk for vitamin D deficiency as they typically have lower sun-to-skin exposure, reduced digestive efficiency, and less effective cutaneous vitamin D production in the skin. Therefore, additional fortified food products and daily multi-vitamins providing 10 to 20 µg (400 to 800 IU)/day are adequate to maintain healthy serum 25(OH)D concentration of 15 ng/ml.

Identify the nutrients and dietary factors that are related to cancer

ALCOHOL PRESERVED/RED MEAT SODIUM AFLATOXIN PROCESSING CHEMICALS

Explain the types of exerciseand the additional nutrients that each require

Aerobic exerciserecruits large muscle groups and a large proportion of slow-twitch, type Imuscle fibers. Type I fibers are specialized for performing repeated contractions for long periods of time using the "oxidative," or oxygen-requiring, energy transformation pathway. Aerobic activities are performed at intensities that can require light, moderate or vigorousamounts of metabolic effort, which are delineated in most fitness settings by heart rate response and oxygen consumption. To confer the health benefits associated with aerobic exercise, the intensity must be sustainable for at least 20-30 minutes. Aerobic exercise exceeding 90 consecutive minutes in duration qualifies as endurance exercise. Anaerobic exerciserecruits fast-twitch, type IImuscle fibers. Type II fibers contract powerfully and immediately and are sustained by non-oxygen requiring pathways. There are several modes of resistance (or strength) exercise that activate the anaerobic energy systems, such as weight lifting, sprints, and calisthenics. Anaerobic exercises are programmed in intervals, bouts, sets or reps that typically utilize more than 85% of contractile force and capacity, and last anywhere from 30 seconds to two minutes. Anaerobic exercise should be performed at least 2-3 times per week at an intensity high enough to elicit muscle injury. The basic tenants of sports nutrition, though, are grounded in the fact that, during exercise, virtually all muscular failure occurs as a result of energy system fatigue. That is, the rate of work within the muscle cannot be maintained because ATP (energy) is in too short supply and the muscle can no longer maintain the same level of contractile capacity and power. Thus, whether one's training is focused on strength or endurance, the training diet generally focuses on more energy nutrients and, perhaps more importantly, on strategic timingto support the conditioning and performance of the primary energy systemthat will engine the activity or sport. Additional fluids are required to offset sweat and metabolic water losses incurred during and shortly after exercise. The amount needed is dependent on environmental conditions that influence sweat rate, the metabolic rate (which is directly proportional to exercise intensity and duration), and one's capacity to dissipate heat using non-evaporative mechanisms. In shorter stints of anaerobic exercise, even in higher temperatures, hydration is normally not an issue. However, during events with repeated power-based performances, and for aerobic exercise that is long duration, fluid intake should be methodically dosed and timed before, during and after exercise. For hot weather conditions, the average exercising person performing moderately heavy, exercise is estimated to accumulate approximately 6.88 kcal of heat and to lose nearly 12 g of sweat per minute such that 0.72 L of water per hour must be replaced. In cooler temperatures, just 2 cups of water per hour of exercise is estimated to adequately replace hourly sweat losses. Energy expended performing physical activities is a highly variable component of total daily energy expenditure (TDEE). The energy expended during physical activities is most accurately estimated using direct calorimetry, whereby the sum of energy expended during physical activities as well as the non-exercise activity thermogenesis (NEAT), and excess post-exercise oxygen consumption (EPOC) is measured and added to the Cunningham equation (RMR) and the thermic effect of digestion. Most validated algorithms yield, for the average-sized adult exercising in the moderate-intensity range for 30-60 minutes most days of the week, about an additional 300-400 calories (4-5g/kcal or 8 calories/lb.) per day. However, the Katch-McArdle equation (BMR) may be a more accurate estimate of individual calorie needs for people with higher than average lean mass, such as bodybuilders and strength athletes. Carbohydratestypically represent a similar proportion of total calories in the training diet as compared to the regular daily diet. For endurance training, where additional calorie needs are significantly higher, daily carbohydrate needs can reach nearly 70% of total needs as compared to protein and fat. The American College of Sports Medicine has developed guidelines for both moderate (1 hour) and high (1-3 hours) levels of daily exercise that range from 5-10 grams of carbohydrate needs per kg of body weight per day (or, 2-5 grams per pound per day). The timing and amount of carbohydrate intake in the days and hours leading up to a long bout of exercise can delay fatigue onset and improve the perception of intensity making exercise more pleasurable. Consuming even a relatively small amount of carbohydrates (30-60 grams) before and after endurance and resistance exercises helps to enhance muscle energy (i.e., glycogen) stores for performance and to promote muscle recovery (i.e., anabolism). A small dose of carbohydrates consumed during exercise can also maximize performance in endurance events that last more than 90 minutes. Although there have been very few studies of the requirement forprotein for individuals undertaking high levels of exercise, it is commonly believed by athletes and fitness enthusiasts that higher-than-normal protein intake is required for optimum physical performance. The reality is that for most muscularly-active adults, the additional protein needed to support muscle recovery, atop regular daily protein turnover, can be satisfied with a diet that is12-15% protein calories. Thus, a diet that is 500 to 1000 calories higher to offset exercise would also have a higher protein intake of around 1.2-1.6 grams per /kg/d, and for endurance exercise where calorie expenditure is significantly higher, like 4000 calories per day, protein calories expressed by body weight appears much higher, ranging from 1.8-2.0 g/kg/d. So, while active people do need more protein, it is not disproportional to the increased need for energy. Dietary fatintake guidelines for exercise training follow the same 25-35% AMDR as recommended for inactive adults, even with increased calorie intake. The quality of fat in the athlete or training diet should also be similar in pattern to the typical diet: that is, being limited in solid fats and adequate in essential fats, particularly omega 3 fatty acids. Some experts suggest that for extreme endurance exercise (over 2 hours), several weeks of eating a relatively higher fat diet preceding the event may provide beneficial changes in the utilization and serum levels of free fatty acids. However, there has been less investigation into ergogenic strategies centered on meal timing in regards to fat intake since exercise duration is typically supplied in ample amounts by adipose tissue stores. Consumption of specific micronutrientsabove the RDA has not been shown to exert any ergogenic effect on performance for the vast majority of athletes and active adults who are healthy and adequately nourished. In fact, research investigations studying many types of sport-demands have shown that competition and exercise regimes do not impose any special demands for any of the 6 major classes of nutrients beyond what is needed to replace exercise losses. For an athlete diet that is inadequate in one or more of the several critical nutrients, nutritional and pharmacologic aids, or even various supplements, may be considered. Ergogenic aids Nutrients and nutrient-related compounds are included in one of several classes of ergogenic aids that are marketed to provide short- and long-term energy for exercise and to promote muscle tissue growth post-exercise during recovery. Several popular ergogenic nutrient compounds are isolated from whole foods or engineered to mimic fractional food components for dietary supplements. There are also varying amounts of several non-nutritive, pharmacologic compoundsin natural foods and supplemented to the diet which may have ergogenic benefits. These compounds are most often promoted for enhancing fat burning (e.g., caffeine and carnitine), or for improving the muscle's tolerance to anabolic exercise (e.g., creatine and androgens).

Recall food serving guidelines and recognize foods that provide nutrients for each of the age groups

An infant's readiness to eat solid foodsis entirely dependent on size, strength and the ability to stiffen their neck enough to sit upright. Once the infant demonstrates signs of readiness and can sit upright, parents may begin soft liquid iron-fortified cereal mixtures to supplement breastfeeding. Pureed fruits and vegetables usually follow. The first foods in each of these categories must be easy to assimilate, nutrient-rich and non-allergenic. The first grainsshould be moderate in fiber content and low in gluten or gluten-free, as wheat is a common culprit of gastrointestinal stress and eczema-like skin reactions. Accordingly, at least in the first few exposures to grain foods, wheat should be avoided. Rice, oat, and barley cereals are common first grains in the US because they are low in the allergenic protein, gluten. Several other grains, like quinoa and amaranth, are more commonly used in other countries; in the US, they are marketed as healthy alternatives to rice. Dried and instant grain cereals are popular in the first foods market. They are often fortified with iron and contain additional nutrients such as DHA and probiotics. Products that develop infant motor and feeding skills, like teething biscuits, often feature grain foods. Some later-stage grains are formulations of mixed grains featuring fruit and vegetable powders that blend into the puree. The first fruits and vegetables should have a relatively high pH and a good amount of soluble fiber. They should be peeled, cooked, pureed and strained for simple swallowing and digestion. Fruits and vegetables that are porous, or that will be left intact for the puree, should be purchased organic or in varieties grown locally to ensure that less chemical preservatives are used. If organic produce is unavailable or cost-prohibitive, produce must be thoroughly washed, and skins, or peels, of those fruits and vegetables listed in the Environmental Worker's Group's "Dirty Dozen" should be avoided entirely. 100% fruit and vegetable juice varieties can be offered to infants older than 6 months; however, they should be limited to no more than four to six ounces per day. Once a single food is well-tolerated for at least four days, another grain, fruit or vegetable can be introduced. As baby begins to tolerate various foods within each food group, an appropriate daily intake for balance should be adopted. At first, daily intake should be two to three tablespoons of grains and three tablespoons of fruit/vegetable servings combined. As the baby's system adapts to digest starches and break down the proteins in grains, animal protein sources may be introduced. Yogurt andcheeseare safe animal foods to introduce first because the proteins that commonly trigger allergic reactions and gastrointestinal intolerances are partially broken down during the fermentation and maturing processes. Infants under one year of age must avoid honey and should avoid cow's milk. Cow's milk should not be substituted for infant formula or breast milk because it provides too little iron and too much protein. As infant growth continues at an accelerated pace after the 8thmonth and breastfeeding taper off, the increasing dietary intake requirements for chromium, zinc, protein, and B12 from foods justify the introduction of meat. First meatsshould be thoughtfully chosen and carefully handled because infants are more susceptible to foodborne illnesses from chemical toxicities and bacterial contamination. In addition, the textures of meats should be soft, easily manipulated by the tongue and cheeks, and sized appropriately so as not to present undue choking risk. Higher-moisture lean meats, like meatballs, scrambled eggs, and minced whitefish are all good meats to introduce first. By their first birthdays, infants are typically following a more regular meal pattern that divides around 1000 calories across the anywhere from five to six meal occasions. After the age of one, whole cow's milkmay be added to the toddler diet. Since babies and young toddlers should get about half of their calories from fat, whole dairy milk, which is approximately 4% milk fat, is preferred over skim and reduced-fat versions. By age two, fat consumption can be gradually decreased, and whole milk can be substituted for 2%, lower-fat milk, which will provide the calcium needed for bone growth without interfering with the infant's appetite. Snack timing is a major factor influencing the food intake of toddlers. Toddlers have small stomachs that fill to a level to suppress hunger with very small amounts of foods and drinks. During the later hours of the day, or when activity levels have lowered, snacks should be limited in order to ensure toddlers consume the nutritious elements of their dinner meals. Despite its flaws, snack time is an excellent way to expand the selection of less common fruits and vegetables after around 18-24 months. When introducing new fruits, it is important to monitor for allergic reactions; like with berries for instance, which have birch-pollen that can cause itching and oral inflammation shortly after consumption. Throughout the toddler period, foods that may cause choking should be avoided. Larger pieces of food should be quartered, cut lengthwise and then from there sliced into small pieces until they are small enough not to pose a choking risk in the event of inadequate chewing. Small foods that cannot be cut or mashed like whole nuts, candies, popcorn, or even chunks in crunchy nut butters should be avoided until after toddlerhood. Other toddler safety feeding-related concerns include temperature control and post-feeding reactions to potential allergens in the foods listed in Figure 9 Primary and middle school-aged children in the 5-13 age range who eat lunch at school are served at least one serving from each of the food groups daily. The National School Lunch Program, funded by the USDA, ensures that school lunches, and in some districts breakfasts too, satisfy at least one-third of the RDA for selected nutrients and are restricted in calories from sugar and fat. Adolescent 14 to 18-year-olds need a higher number of servings from each of the major food groups compared to kids who are in the 9-13 age range. Adolescent boys need roughly 20% more servings of each of the food groups than girls, except for dairy. Adolescent girls, 9-13 years old, have additional daily fruit, vegetable, meat, dairy and oil requirements compared to their 4 to 11-year-old counterparts, but the same intake recommendations for grains. Older teen girls, ages 14-18, have the same intake guidelines for fruit, meat, oil and dairy as girls in the 11-13 age group, but slightly higher needs from the vegetable and grain groups. Teens who are vegan must include a greater number of servings of protein-rich legumes and nuts to satisfy protein needs compared to non-vegan teens who consume animal meat equivalents. Adolescent girls and boys, by and large, do not get enough fruits and vegetables. The most common vegetables in this age range are carrots, white potatoes, corn, and tomatoes. These foods provide the majority of vegetable-provided fiber and vitamins A and C in the adolescent diet which, even when combined, are inadequate to meet the intake guidelines. Adolescents, especially teens, also get too many calories from poorer choices within the groups, including soft drinks, beef, cheese, and ice cream. Another major concern for adolescents and teens is their snacking pattern. Approximately 25-35% of the daily adolescent calorie intake comes from snacking, with a reported average intake of one to seven snacks per day. The most problematic foods like chips, cookies, crackers, and other processed snacksare often consumed at snack time, as is soda, which alone provides an estimated 8% of total adolescent caloric intake, on average. Older adults, as compared to those under the age of 51, need fewer servings per day of every food group except dairy and oil. For adults over 51 years, daily fruit, vegetable, and meat intake guidelines are reduced by one-half cup, and grain servings are reduced by one full cup. The ideal meal patternfor older adults is small and frequent. Seniors should eat five to six small meals a day to mitigate insulin highs and lows and, for some, gastrointestinal discomfort or breathing troubles caused by eating large meals. The largest meal of the day should not be dinner, because older adults tend to sleep earlier and have more digestive problems when they lie down that can interfere with their rest. Older adults have changes in taste acuitythat make foods taste blander. They are also often placed on restricted diets low in fat and salt so that the taste and smell of foods are less appealing. Many seniors have eyesight and motor skill feeding issues that make eating with a fork, knife and spoon difficult. Motor problems with swallowing can require that foods be prepared in small pieces to prevent choking. Adequate protein intake is critical for older and elderly populations. Protein can be supplemented in snacks and drinks and should be the focal point of most meal periods. Adequate vitamin K for bone health can be achieved by about one cup of dark green vegetablesdaily.

Recognize foods that provide significant disease preventative nutrients

Animal meatis a high-quality source of dietary protein and minerals. Lean and extra lean cuts of poultry, fish or pork should be consumed 1-3 times daily in an amount around the size of a deck of cards. At least two servings each week should come from AHA-designated "heart healthy" fish-that is, fish containing less than 16 grams of fat, less than 4 grams of saturated fat and at least 500 mg of omega-3 fatty acids per 3 oz. cooked serving. Fatty cold-water fish like salmon, mackerel, tuna, herring and sardines contain high amounts of omega-3s. Fish like bass, tilapia, cod and shellfish contain lower levels of omega-3s but are generally leaner than fatty cold-water fish. Farmed fish usually have higher levels of EPA and DHA than wild-caught fish, but those levels vary depending on the composition of the fish's diet. This is true for other animal species, as well. For instance, beef is traditionally very low in omega-3s, but beef from grass-fed cows contains higher levels of ALA than meat from grain-fed cows because of diet alone. Oilsprovide essential fats and fat-soluble vitamins in the diet. Olive, rapeseed, marine and mustard seed oils are the richest sources of monounsaturated fats. Polyunsaturated omega 3 and omega 6 fatty acids are prevalent in, among others, flaxseed, pumpkin seed, canola, soybean (not hydrogenated), walnut, safflower, sunflower and sesame oils. Liquid oils that are high in monounsaturated fats should be used in cooking and baking as much as possible in place of saturated coconut, palm, and palm kernel oils, butter, and solid vegetable oils, like Crisco. Oils should be purchased in opaque bottles to preserve light-sensitive nutrients, such as vitamin E. Monounsaturated fatty acid-rich peanut and extra virgin olive oils stand up well to cooking, which is important to prevent carcinogenic changes to fatty acids that occur when vegetable oils are heated to very high temperatures. Hydrogenated and partially-hydrogenated oils that are made into margarine, shortening or into texturizing or preserving ingredients are often hidden in processed foods. Convenience foodssuch as frozen pizzas, biscuits, microwave popcorn, peanut butter, and some breakfast cereals, for example, that contain the word "hydrogenated" anywhere in the ingredients list should be avoided entirely. Milkand yogurt are good sources of essential nutrients and can also be used to replace butter and oil in recipes. The AHA recommends that dairy foods provide 130 calories or less per 8 fl oz. and that a 6 oz serving of yogurt has 20 grams or less of total sugar per serving. With the recent boom in smoothies in the health food market, the AHA added a new guideline that smoothiesshould provide 200 calories or less per 8 oz. serving, or 300 calories for 12 oz. There should be 2 teaspoons (8 g) or less of added sugar per smoothie serving, and at least one whole serving of dairy or dairy alternatives (e.g., nut/grain/soy-based milk; not ice cream) or a whole fruit or vegetable serving (not juice concentrate). Whole-grain cereals, bread, pasta, and snack bars are made from whole grain seed flours, are typically high in fiber, and usually have a low GI. Superior grain products are labeled "100% whole grain" or "100% whole wheat." With the growing popularity of meal replacement and snack bars, the AHA has added a new requirement that recommended grain-based snack bars be a "good source" of dietary fiber (i.e., providing 10% or more of Daily Values) and contain 7g or less of total sugars per serving. If the bar is a "good source" of dietary fiber (20% or more of Daily Values), the allowance for sugar is 2 grams higher. Grain-based snacks and desserts, like doughnuts and cakes, tend to include a great deal of added fat to enhance mouthfeel and texture and, for that reason, should be consumed sparingly. Baked grain products should be avoided in the daily diet as well because they are often very high in either sugar or salt. Seedsthat are rich in swellable fiber can be effective to replace fats in baked grain pastries. For example, chia seeds and flax seeds can effectively replace eggs in many pastry recipes. They provide moisture and binding properties that enhance the texture of products like muffins and cookies. Leguminous seeds and beansare also high in viscous fiber, have relatively low glycemic effects and, in addition, provide magnesium and phytosterols in the diet. The beans and legumes highest in fiber include peas, lentils, and pinto, black, red and kidney beans which can provide up to 10 grams of fiber per serving. Bean soups varieties are excellent sources of fiber but, like all soups, contain significant levels of sodium. The "low sodium" designation for soups, like other food products, requires at least 25% less sodium than a suitable reference food with "regular" sodium levels, which can still be considerable. Effective ways to reduce sodium in soups made from scratch include using potassium chloride salt substitutes and larger quantities of other traditional soup spices like basil, thyme or oregano. Diversifying the spice profile of foods other than soups with more dominant, forward spices such as cumin, pepper or paprika may also help sensory acceptance as these flavors can help compensate for missing salt. Nutsare also good sources of soluble fiber and phytosterols. The nuts richest in phytosterols are pistachios, cashews, and peanuts, which although technically legumes, are marketed and packed as nuts. Peanut butter, however, has half the phytosterols that peanuts have highlighting the significance of processing effects on food content. The FDA has acknowledged the emerging evidence of a relationship between nut consumption and lower cardiovascular disease risk by approving the following qualified health claim for nuts: "Scientific evidence suggests but does not prove that eating 1.5 ounces per day of most nuts as part of a diet low in saturated fat and cholesterol may reduce the risk of heart disease." Raw nut varieties (i.e., not oil roasted) that are "unsalted" or "lightly salted," meaning they have 50% less salt than "salted" varieties, still contain over 140 mg of sodium per one-ounce serving. As such, the consumption of nuts, like soups, should be carefully monitored in the diet.

Recall BMI categories

Anthropometricassessments are most commonly used to measure weight loss status. Scales, tape measurers, and electric devices are used to determine changes in body dimensions and composition of tissue mass. More sophisticated techniques and tools are available for use in controlled research protocols but, for most practical clinical and counseling applications, an easy to interpret and relatively reproducible assessment of weight loss over time is bodyweight for height (BMI). Though well-correlated with bodyweight loss, BMI, may inaccurately reflect intervention-related changes in body composition as it does not account for bone and muscle density, frame size, and fat distribution.

Recall what dietary factors can minimize oxidation and inflammation

Anti-inflammatory diets are associated with reduced risk of cardiovascular disease and ischemic stroke, as well as reduced cancer promotion. These diets are low glycemic, low in saturated and polyunsaturated fats, and rich in omega-3 fatty acids. They usually elicit a conservative insulin response, which favors the conversion to the anti-inflammation eicosanoid EPA, instead of the pro-inflammatory one arachidonic acid. Consuming around two servings of omega-3 rich fish per week or, alternatively, 300-500 mg/day of EPA + DHA supplements may favor lower incidences of fatal myocardial infarction and sudden cardiac deaths, and foods rich in anthocyanin like red wine, apples and strawberries may reduce the pro-inflammatory response by targeting and disabling acute-phase reactant proteins. Supplemental resveratrol may also improve the profile of circulating inflammatory markers, at least temporarily, and may reduce pro-inflammatory gene expression.

Recall the stages and effects of carbohydrate depletion during exercise

As all types of physical activity are sustained by food and nutrients, dietary imbalances that compromise nutritional status may lead to unfavorable performance outcomes. For instance, if too little glycogenis available at the onset of high-intensity exercise, muscle fatigueoccurs as a result of oxygen debt, and lactic acid buildup follows. In longer-duration exercises, muscle fatigue usually occurs as a result of insufficient energy to re-phosphorylate ATP. Blood sugar levels during exercise are maintained by liver glycogen which, along with absorbed carbohydrates, is adequate to replenish blood glucose during exercise. If carbohydrates are not available, the liver can supply about one hour of 70% oxygen consumption capacity (i.e., VO2max) moderate exercise, at which time, liver glycogen levels are about half-used, and the rates of hepatic breakdown and output are steadily reduced. At that point, blood sugar levels drop and "bonking" occurs, which results in extreme exhaustion and energy loss. Continued prioritization of blood, and ensuing muscle glycogen depletion, is known as "hitting the wall." Dehydrationcan alter cardiovascular, thermoregulatory, central nervous system and metabolic functions in ways that adversely influence aerobic- and endurance-type exercise performance. Greater body water deficits may result in more severe performance reductions, which are often further accentuated by heat stress. Dehydration affects performances by lowering blood volume and decreasing cardiac output and is typically associated with a dark urine color. Performance may also be impaired by poorly timed meals. For instance, insoluble fiber eaten prior to exercise may cause bowel movements during exercise, which may accelerate fluid loss. Consuming soluble fiber before exercise may result in added gas production causing flatulenceand cramping. Poorly chosen fluids or re-fuel can also affect GI comfort and blood sugar levels. By way of example, concentrated carbohydrate solutions consumed before or during exercise may cause gastrointestinal problems because carbohydrate absorption during exercise is limited to about 60 grams per hour, so that beverages with high-density osmolarities (i.e., >500 mOsm/L), like the type that is found in drinks that contain >12 g sugar/100 ml of carbohydrate, will most likely result in accumulation of carbohydrates in the intestine. This may lead to cramping, diarrhea, or even rebound hypoglycemia.

Identify the nutrients that are more and less likely to elicit toxicity or deficiency symptoms during adolescence

Ascorbic aciddeficiency, for instance, may impair the quality and quantity of the bone matrix by limiting the hydroxylation of collagenous proline and lysine residues and interfering with osteoblastic adhesion to the bone matrix. Vitamin A deficiency can also cause bone abnormalities due to impaired osteoclastic and osteoblastic activities associated with poor bone growth and mineralization. Excessive intake of micronutrients can also have deleterious effects on children. For instance, too much vitamin D in the diet can lead to high levels of deposited calcium salts in the soft tissues, including the kidneys, heart, and lungs. It can also result in hypercalcemia or high levels of calcium in the blood. Osteomalacia,also known as "adult rickets," is a failure to mineralize bone. Stereotypically, osteomalacia results from vitamin D deficiencyand the associated inability to absorb dietary calcium and phosphorus across the small intestine. This results in incomplete mineralization of the newly secreted bone matrix such that the bone can be deformed under the strain of body weight.Osteopeniaand osteoporosis are conditions related to varying degrees of low bone mass. Whereas osteomalacia is characterized by low-mineral and high-matrix content, osteopenia and osteoporosis result from low levels of both. Osteoporosisis a condition of increased bone fragility and susceptibility to fracture due to loss of bone mass. Skeletal sites that are rich in trabecular bone are often sites of osteoporotic fractures, such as the hip, femoral neck, and vertebrae of the spinal column.

differentiate among types of supplemental products that are developed for exercise

Beveragesare a great choice for replenishing the body during exercise and a great medium for protein and ergogenic compounds during the post-exercise period. Supplement powders are formulated to be added to milk, juice or water typically featuring whole proteins and free amino acids. Whey proteinis a whole protein that is the byproduct of the manufacture of cheese. It is a typical ingredient in low-cost commodity protein powders often marketed as having a high biological value. While whey is an adequate protein to sustain a positive nitrogen balance, and may even be superior to some other whole food-proteins for nitrogen retention, it does not appear to increase muscle mass in athletes more than other whole protein sources if total protein intake is adequate. Single, free amino acid supplementsand protein-peptide chainsare allegedly distinguishable from whole proteins on the notion that they are absorbed more easily. Although this has not been proven scientifically in healthy, weight- training adults, several such supplements are marketed for anaerobic exercise power and recovery. Glycineand arginine, for example, are often featured in free amino acid supplements since they are pre-cursors that feed into pathways for creatine phosphate synthesis. Similarly, beta-alanine, a non-essential amino acid metabolite needed for acid-buffer carnosine, a neurotransmitter, is also marketed for optimal acute exercise recovery.

Recall some of the gastro-intestinal complications that may occur before or during exercise

Blood flow and neuromuscular signaling are reduced by as much as 80% at the onset of exercise which, to varying degrees, based on training and exercise type, can compromise intestinal nutrient and fluid absorption. Pre-competition anxiety can trigger the release of catecholamine hormones and speed the rate of transit, resulting in incomplete absorption of the pre-meal, which can cause gastrointestinal discomfort, flatulence and loose stool (i.e., diarrhea). Postural changes, like aero positioning during cycling, can have the same effects from intra-luminal pressure imbalances. Mechanical damage to the intestinal walls from repetitive high-impact running, for example, can also cause cramping and even light bleeding. Even swallowing too much air as a result of increased respiration while drinking from water bottles can result in mild-to-moderate stomach distress. Gastric motor activity, and consequently gastric emptying, are governed by neural receptors found in the gastric musculature of the proximal small intestine. The rate of gastric emptying during exercise depends on exercise intensity and duration. It is also influenced by a variety of factors including, but not limited to, the caloric content, volume, osmolality, temperature and pH of the ingested food or fluid matter. While it seems that during light-to-moderate exercisegastric emptying occurs at a rate similar to that during rest (on average, 2.0-2.5 kcal/min), during more intense exercise, gastric emptying may be inhibited. Fluid absorption in the small intestine is stimulated by glucose and sodium and, to a lesser extent, by fructose and other electrolytes. Glucose and sodium are absorbed via a common membrane carrier in the mucosal epithelium of the proximal small intestine so that the potentiation establishes an osmotic gradient for fluid absorption.

Identify the hormones that initiate bone growth and those that accelerate bone loss

Bone formation begins in utero when the bones consist primarily of soft and flexible hyaline cartilage. By birth, the bone has more features and details, like a medullary cavity with blood vessels and bone tissue more prominently pushing out from the center of the epiphyses region of hyaline cartilage. Bone ossification centers develop during the first phase of bone growth while the size of the bone increases. Bone growth, particularly the longitudinal type, is driven by the action of human growth hormone, secreted from the anterior pituitary. Bone lengthening takes place in the epiphyses region, or proliferative zone, of the long bones. Bone cells in the epiphyses region undergo mitotic division, causing such an increase in cell number that the bone is lengthened. Duringbone modeling, bones undergo lengthening and vascularization. The extra vasculature delivers osteoclast and osteoblast cells to the matrix of spongy and trabecular bone tissues. Osteoblasts are activated by estrogen, parathyroid hormone and serum vitamin D. If local bone matrix minerals, phosphate, fluoride, and magnesium concentrations are adequate, osteoblasts are stimulated to form new bone. Bone collagen production by osteoclastsis dependent on circulating vitamin C. Vitamin C is a co-factor in the hydroxylation of lysine and proline in the synthesis of osteoid, which is the collagen component of bone. Osteoblastssecrete osteoid, which is subsequently mineralized by osteocalcin. Once they have finished secreting bone matrix, many of the osteoblasts transform into osteocytes--long-lived bone cells that makeup nearly 95% of all adult compact bone. Bone modeling during childhood and early adulthood exceeds the rate of the bone breakdown so that there are net gains in the quantity of bone tissue in the matrix and mineral compartments. Soon after all of the cartilage in bone tissue is replaced with a strip of compact bone, and the medullary capillary is filled with yellow fat (i.e., bone marrow), the bone will no longer grow in length, but will continue to gain density and mass upon physical stressors and forces as long as adequate nutrients are available. After peak bone density is reached in early adulthood, bone metabolism switches to the remodeling phase. The remodeling phase consists of a constant process of bone mineral and organic bone matrix resorption, or breakdown, and formation that predominates continues throughout life. During remodeling, bone breakdown and formation activity are in sync. Osteoclasts first dissolve a section of bone by secreting certain enzymes and acids, then osteoblasts invade the newly created space and secrete bone matrix. The full bone remodeling cycle from osteoclast resorption to final osteoblast mineralization lasts approximately 40 weeks. Bone resorption and formation are equally paced until the mid-30s. At that point, the rate of bone resorption begins to exceed bone formation, which leads to age-related bone mass loss. This effect is multiplied during the fourth decade of life when growth Hormone (GH) production begins to decline and, by the fifth decade, when growth factor secretion drops by more than 50%. The decline in the GH-IGF-I axis results in decreased bone tissue synthesis and, therefore, reduced bone mass. The loss of reproductive hormonesfrom the ovaries and testicles accelerates bone loss.

Recall the major differences between human milk and commercial infant formulas

Breast milk supplied from the human mother is the premier source of nutrition for newborns and young infants. Breast milk delivers irreproducible antibodies and lymphocytes, which give the newborn greater resistance to environmental pathogens that can lead to sickness and infection. Breast milk provides other bioactive substances, like endocannabinoids, which act as appetite stimulants and satiation signals to help regulate the new infant's appetite. Cow's milk formulasfeature whey proteins that are specially formulated to resemble the human milk protein, alpha-lactalbumin. These proteins are marketed as hydrosylated, or "pre-digested," meaning they are in smaller peptide chains that less resemble the larger, potentially allergenic, beta-lactoglobulin cow milk proteins from which the protein was derived. Cow formulas are also stripped of a portion of their mineral concentration, then enhanced with a dose of added essential linoleic and linolenic fatty acids from vegetable oil in an effort to closely resemble human breast milk. Soy formulas. have a significantly smaller market share compared to cow formulas. They typically feature considerably more total protein and have less than half the total fat of human milk but are lower in amino acids and devoid of dietary cholesterol—an important nutrient for infant brain development. Like cow formulas, soy formulas have added long-chain polyunsaturated fatty acids from vegetable oils but, uniquely, they also feature added docosahexaenoic acid, or DHA, and arachidonic acid, or ARA. Cow's milk formula is higher in iron than human milk because lactoferrin, the form of iron in human breast milk, is highly bioavailable. Soy formulas have the most iron per serving to account for the poor bioavailability of iron from plants but can, as a result, be associated with constipation in young infants. Most commercial formulas, especially those intended for babies older than 4 months, are fortified with iron and zinc.

Explain how pregnancy impacts daily nutrient requirements

Changes in smell and taste sensitivity and food preferences in pregnancy may cause imbalances in daily food intake that are deleterious to optimal fetal and maternal recovery outcomes. women's changing sense-perceptionduring pregnancy and the effect of these changes on maternal nutritional status is not entirely understood, most pregnant women report some level of increase in their sensitivity to odors and taste perceptions that stimulate or mitigate appetite signals. Reduced sensitivity to pleasurable tastes and smells can also result in cravings for more salty, sweet, acidic or spicy foods than those that are satisfying when not pregnant. Pregnancy food cravings have been studied more extensively, and while the exact underlying mechanism is also not clear, there are many postulations rooted in psychology, genetics, neurology and even immunology. For instance, neurochemical sensitivity to leptin signaling in the hypothalamus may be suppressed in pregnancy so that the hunger pathwaysare left unopposed. In the first trimester, many women also experience symptoms of nausea and vomiting accompanied by weak appetite and, in some, poor nutritional status. Pregnancy-associated hormones such as human chorionic gonadotropin (hCG), estrogen, progesterone, and thyroid hormone are likely involved in the onset of nausea symptoms.

Identify major dietary hazards in the toddler diet

Choke: Peanut Butter Nuts Peeled apple slices raw carrots pickles raw celery whole beans whole kernel corn cherry tomatoes whole grapes berries Pathogens: meat shell fish dairy milk Avocado cantaloupe sprouts honey Allergens: soy dairy nuts wheats

Identify the neural- hormonal responses to energy restriction

Circulating hormones act on the hypothalamus to affect downstream signaling and gene expression pathways that regulate appetite control. During fasting, circulating ghrelin robustly stimulates the first-order orexigenic neurons of the arcuate nucleus of the hypothalamus (i.e., the ARC). Ghrelinactivates agouti-related peptide (AgRP), and Neuropeptide Y (NPY), which project to the second-order paraventricular hypothalamic nucleus (PVN) and the lateral hypothalamus (LH). NPY directly stimulates food intake via activation of NPY Y1 and reduces energy expenditure by a receptor-mediated reduction in tyrosine hydroxylase expression in the PVN. AgRP/NPY neurons directly inhibit POMC neurons at the ARC by obstructing extra-hypothalamic neurons which, downstream, stimulates food intake and decrease sympathetic output to the brown adipose tissue (BAT) in an effort to conserve energy expended as heat. Several types of prescription medications, such as Lorcaserinand Contrave, have been developed to suppress the orexigenic ARC neuron so that appetite is not stimulated. In the initial stages of energy restriction, muscle and liver glycogen stores are hydrolyzed to glucose via glycogenolysis in order to maintain circulating blood glucose homeostasis. With every gram of stored glycogen in muscle and the liver, the body stores three grams of water so that initial weight loss, especially with carbohydrate restriction, is primarily lost water. In fact, depending on the level of restriction, and an individual's glycogen storing capacity, this can surmount to as much as 3 pounds or more across the initial days of weight loss. Also in the initial stages of energy restriction, muscle and adipose triglycerides are hydrolyzed and freed for use throughout the body. As restriction progresses over time, the majority of fatty acids are released from the adipose tissues in response to the stimulation of the adrenergic receptor. The fat loss process is activated at the surface membrane of white adipocytes by two lipolytic enzymes: adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL). Insulin and the catecholamines, adrenaline and noradrenaline, are the two major signaling molecules that regulate lipolysis, and expression of ATGL and HSL. When catecholamines latch onto the adrenergic receptor, they activate HSL and split the stored triglycerides into free fatty acids, which are then mobilized by way of the capillary network to the muscles for oxidation. Caffeine works synergistically with adrenaline to increase the rate of lipolysis by more than two times, and promotes fatty acid oxidation by adrenergic receptor stimulation and activity. Fat oxidation takes place in the mitochondria of muscle cells. Once in the cell cytoplasm, fatty acids are shuttled into the mitochondria through a transporter molecule called L-carnitine. L-carnitine supplementation is promoted for fat loss, since fatty acid transport during exercise may be limited by L-carnitine availability. Acetyl-CoA produced by the beta-oxidation of fatty acids condenses with oxaloacetate to, together, enter the citric acid cycle. During each turn of the cycle, two carbon atoms leave the cycle as CO2 in the decarboxylation reactions catalyzed by isocitrate dehydrogenase and alpha-ketoglutarate dehydrogenase. Thus, each turn of the citric acid cycle oxidizes an acetyl-CoA unit while regenerating the oxaloacetate molecule with which the acetyl-CoA had originally combined to form citric acid. Key signaling molecules AMPK and PGC-1α (peroxisome proliferator-activated receptor γ coactivator 1α), which both stimulate the mitochondria to burn fat and sugar more efficiently, are stimulated during energy restrictions and fasting. Alpha-lipoic acid (ALA) increases AMPK signaling and fat burning, and drugs have been developed to artificially increase the rate at which we expend energy.

Distinguish between colostrum and fore milk

Colostrum is a thick and high-protein secretion that is sweeter and slightly more yellow than normal breast milk. It is produced during the first few days after birth in volumes averaging 40-50 ml. Colostrum contains high levels of protein antibodies including immunoglobulin, principally, secretory immunoglobulin A (sIgA), which coats the intestinal mucosa and prevents bacteria from entering the cells; white blood cells that kill micro-organisms; whey proteins (lysozyme and lactoferrin), which kill bacteria, viruses and fungi; and oligosaccharides that prevent bacteria from attaching to mucosal surfaces. Antibodies and immune cells in colostrum pass directly through the infant's GI tract into circulation which, interestingly, is the only time in our entire lives that we absorb whole protein. Colostrum seals the permeable spaces in the intestines, which initiates the removal of the meconium (i.e., first stools) from the intestinal tract. As the first week of life progresses, colostrum production decreases and normal breast milk production and secretion increase. Breast milk composition is different and more variable than colostrum. Breast milk contains complex proteins, lipids, carbohydrates and other biologically active components that change in concentration throughout the lactation period and even during the course of one feeding. Milk begins to be produced in larger amounts between 2 to 4 days after delivery, making the breasts feel full, or engorged. On the third day, an infant is typically consuming 300-400 ml of milk per day, and by the fifth day, 500-800 ml. From day 7 to 14, the milk is called transitional, and after 2 weeks, it is called mature milk.

Identify foods that provide significant sources of critical pregnancy nutrients

Designer shakes, bars, cookies, teas, and juice products have been developed to feature these nutrients at a level that usually provides around 50-70% of the additional pregnancy iron needs, at the top end, all of the folate needs and, depending on the product positioning, a significant portion of the increased fiber, protein and/or DHA needs, to name just a few. Prenatal beverage shakes and smoothies are also good platforms for adding micronutrients and dosing healthy amounts of added fiber, calcium and protein. Most of the products marketed in the pregnancy and lactation category are sweet and are perceived as desserts. Other less foundational prenatal food products, such as teas and candies, may be formulated with compounds that help with common pregnancy and lactation problems. For instance, teas are now adding herbs thought to help with nausea and all sorts of products add fenugreek extract to help stimulate lactation. Ready-to-eat breakfast cerealshave one of the most concentrated vitamin and mineral profiles of any food in the human supply. Micronutrient levels are designed to meet 100% of the daily needs for non-pregnant women. The breakfast meal platform is an effective one for preventing nutrient deficiencies because breakfast choices are often limited and purchased repetitively for home consumption. Dry, ready-to-eat cereals are especially effective because they can be sprayed with liquid vitamins and minerals that supply almost 100% of the non-pregnant-to-pregnant and lactation nutrient requirement gaps without affecting the sensory qualities of the cereal. If paired with a 6-8 ounce serving of vitamin A and D-fortified milk, the meal provides 8 grams of protein, additional B vitamins and, most importantly, riboflavin — a relatively sparse micronutrient in most diets. By adding a fruit serving atop the meal, women can secure additional vitamin C to enhance absorption of other micronutrients, like food folate. Fortified grain floursmade into bread and pasta also provide a good portion of the RDAs for many nutrients, especially iron, folic acid, and B-vitamins. However, these products lack the nutrient punch of ready-to-eat breakfast cereals because they cannot be sprayed with special liquid vitamin and mineral mixes after baking. The powdered vitamin and mineral mixes are added to flours prior to baking may change the physical and sensory characteristics of bread and pasta products, and therefore must be used more judiciously. Natural whole foods and meals that are not fortified, but rather naturally rich in nutrients, can also effectively meet the needs of pregnant and lactating women. Their consumption must simply be planned more carefully to ensure that the nutrient density of the diet is adequate. For instance, rice, quinoa, and oats are excellent whole grainsthat naturally contribute additional protein, essential fats, and fiber. Legumes, too, are typically high in fiber and can provide the additional 1-2 grams of daily essential fatty acids needed for pregnant women. Some legumes, like garbanzo beans, are also rich in folate and can provide up to 200 mcg per 1/3 cup serving. Iron from legumes can also help meet the nutritional demands of reproduction but, unfortunately, dietary iron is only about 10% absorbable. Plant foods, specifically high phytic acid legumes and seeds, should be paired with ascorbic acid-rich fruits and vegetables to maximize iron bio-availability. Fruits and vegetables should be consumed often with meals and as snacks to enhance the overall daily nutrient density and mineral absorption, and to curtail symptoms of morning sickness and constipation. Fruits also provide vitamin Cthat is needed to support fetal ascorbic acid uptake and to sustain the concentrations secreted in breast milk. Fruit intake is especially important in the lactating diet, since postpartum vitamin C and A needs increase by 40% and 68%, respectively, during that period. Just one serving of a vitamin C and A-rich fruit or vegetable, like strawberries or red bell peppers, will entirely close the gap between daily non-pregnant and pregnant RDAs. Animal meatis a more efficient form of iron, zinc, and protein for pregnant and lactating women. Red meat, chicken and certain fish also provide significant amounts of dietary fat. Species that are high in saturated fat and cholesterol, like beef and dark poultry meat, should be consumed less than species of meat that are lower in fat overall, or species that are higher in the preformed essential fats DHA and EPA, like fish and specialty eggs. Guidelines for fish intake during pregnancy and lactation are the same as for non-pregnant women and should total at least eight ounces per week.

Identify factors related to dysfunctional nutrient processing in the GI track

During chemotherapy and radiation therapy to the head or neck area, the glands that make saliva can be damaged so that patients may have dry mouthand trouble swallowing. Chemotherapy can also cause constipation, which is characterized by frequent and hard, dry stools that are difficult to pass with accompanying symptoms including belching, gas, stomach cramps or pressure in the rectum. Mild to severe diarrheacan also occur as a result of cancer treatments, especially with therapy to the abdomen or pelvis area, as damaged cells in the lining of the large and small bowels lose their ability to slow the passing of foods and liquids which ensures adequate absorption of nutrients and water. Additionally, biological therapy and some types of chemotherapy and radiotherapy to the abdomen, small intestine or colon can cause nausea, vomiting, or both. Vomiting can occur immediately post-treatment, or as late as 1-2 days thereafter, and is usually preceded by nausea or upset stomach, and is often triggered by food odors. Alcoholcan act as an irritant in the cancer patient's diet, especially in the cells of the upper gastrointestinal tract. Additionally, bacteria that normally live in the colon and rectum can convert alcohol into large amounts of acetaldehyde, a chemical that is potentially carcinogenic. Alcohol may also contribute to a carcinogenic GI environment by enabling other harmful chemicals, like those found in cigarettes, to enter the cell lining of the upper digestive tract more easily. High-fat mealselicit larger volumes of bile secretion into the small intestine. Excess bile and high fat decaying food matter in the colon can promulgate bacterial fermentation and carcinogen production. Carcinogenic compounds that may mutate colon cell DNA include apcholic acid, more than twenty types of fecapentanes and short-chain fatty acid compounds. Heterocyclic amines or N-nitroso compoundsare generated when heme-iron and fatty acids in meat are cooked at high temperatures, and also in the gastrointestinal tract following consumption of red and processed meat.

Explain ketosis including what ketones are made of and what tissues they are used

During fasting, starvation, or ketosis-inducing diets that include less than 20 grams of carbohydrates per day, the body switches to a metabolic system that increases ketogenesis. Excess levels of fatty acids or acetyl-CoA from beta-oxidation are diverted to the liver for conversion to acetoacetate and beta-hydroxybutyrate. Acetoacetate and beta-hydroxybutyrate are two water-soluble ketone bodies that are produced, along with acetone, in the liver. Ketones can be further metabolized to isopropanol/acetone by acetoacetate decarboxylase, which is excreted in breath or urine. Or they can be hydroxylated to acetol for subsequent propylene glycol formate and later, acetate formation. Ketones and ketogenesis intermediates are released by the liver into the blood and taken up all cells that have mitochondria to undergo ketosis, or reconversion to acetyl-CoA, and subsequent use in the cell Krebs's cycle. Unlike free fatty acids, ketone bodies cross the blood-brain barrier and are available for glycolysis in the cells of the central nervous system. The glycerolthat is released into the blood during the lipolysis of triglycerides in adipose tissue is taken up by the liver. Here, it is converted into glycerol 3-phosphate by the action of glycerol kinase, and subsequently, oxidized to dihydroxyacetone phosphate which is, in turn, converted into glyceraldehyde 3-phosphate by the enzyme triose phosphate isomerase. From there, the three carbon atoms of the original glycerol can be oxidized via glycolysis, or converted to glucose via gluconeogenesis.

Identify factors related to dysfunctional nutrient processing in hepatic tissues

Dyslipidemia, or high blood cholesterol, is the result of increased hepatic cholesterol and fatty acid production from excess sugarsand suppression of lipoprotein lipase, the major mediator of cholesterol clearance. Very low-density lipoprotein (VLDL) is metabolized into remnant lipoproteins (apoB) and small dense low-density lipoprotein (LDL), which both promote atherosclerotic plaque formation. Additionally, the triglycerides in VLDL are transferred to high-density lipoprotein (HDL) by cholesterol ester transport protein, which makes HDL a more suitable substrate for hepatic lipase action and clearance when it passes through the liver. This exacerbates the levels of small dense LDL particles because fewer HDL particles are available to participate in reverse cholesterol transport from the vasculature.

Describe the role of sodium in reducing hypertension

Even a modestsalt reductionin the diet totaling less than one teaspoon per day can decrease systolic and diastolicblood pressure in individuals with and without hypertension. Low sodium is the cornerstone of the Dietary Approaches to Stop Hypertension (DASH) diet, although it also emphasizes the importance of consuming ample amounts of potassium-rich fruits and vegetables. A series of studies have demonstrated significantly lower blood pressure can result from as little as several weeks of high fruit and vegetable intake featuring at least eight servings per day. Interest in garlic and its potential to prevent cardiovascular disease began with observations that people living near the Mediterranean basin had lower mortality from cardiovascular disease. The bioactive organosulfur compoundsin garlic may increase the production of nitric oxide, allowing gaseous signaling to appropriately relax blood vessels. Garlic compounds may also inhibit the growth and migration of vascular smooth muscle cells, a feature of advanced atherosclerotic lesions, by disrupting platelet aggregation and plaque formation. While no serious side effects of supplemental garlic have been reported, the body of scientific evidence regarding the effect of garlic on hypertension is not yet fully developed and requires further research.

Differentiate between the aerobic and anaerobic energy systems Match a muscle fuel source to an ATP energy pathway Explain the cardio- respiratory response to exercise onset Describe the process in which muscle growth is stimulated Match ergogenic compounds to processing systems that are underlie their mechanics

Exercise begins with a signal from the neuromuscular system. A nervous impulse (i.e., action potential) arrives at the neuromuscular junction, which causes a release of a chemical called acetylcholine. Acetylcholine causes the depolarization of the motor endplate which travels throughout the muscle by the transverse tubules. This stimulates the sarcoplasmic reticulum to release calcium into the muscle cell. Calciumfloods into the muscle cell and binds with troponin, changing its shape, which moves tropomyosin from the active site of the actin so that the myosin filaments can attach to the actin, forming a cross-bridge. The breakdown of ATP releases energy which enables the myosin to pull the actin filaments inwards and so shortening the length of the muscle fiber. When ATP is broken down, the myosin head can, again, attach to an actin-binding site further along the actin filament and repeat the 'power stroke.' Once the nerve impulse stimulus stops, the calcium is pumped back to the sarcoplasmic reticulum, breaking the link between actin and myosin, and the actin returns to its resting position/unbound state causing the muscle to lengthen and relax. This process of muscular contraction can last for as long as there is adequate calcium and ATP stores. Skeletal muscle contraction is fueled by a recyclable chemical stored in the muscle called adenosine triphosphate (ATP). ATP is recycled in the muscle by one of three energy-yielding pathways that transfer chemical energy. Creatine phosphate (CrP)supplies most of the energy for short-term, maximal effort-type exercise. In fast-twitch skeletal muscles, a large pool of CrP and high cytosolic creatine kinase (CK) activity are present. CK locally regenerates ATP using CrP at a rate sufficient to keep ATP and ADP virtually constant over several seconds of high-intensity contractions. Free creatine is re-phosphorylated to CrP by CK using stored mitochondrial ATP in the intermembrane space. Liberated ADP is transported back to the mitochondrial matrix and re-phosphorylated to ATP, and CrP diffuses out of the mitochondria through the cytosol to the sites of ATP consumption thereby closing the cycle. This quick cycle "buffers" the cell's phosphorylation potential until the nutrient combustion system can kick in and will remain the primary system for up to 30 seconds of moderate-to-high intensity muscle contractions. The next burst of energy to support muscle contractions at exercise onset is sustained by the glycolytic system. This system uses local cellular glucose to produce two molecules of pyruvate, which can be used to re-synthesize 2 net ATP, or if myoglobin is adequate, 36 ATP from the TCA cycle. This energy supports the first 2-10 seconds of high-intensity, powerful contractions. During that short period, cellular oxygen is insufficient so that most of the pyruvate is fermented into lactic acidin a process called anaerobic glycolysis. Lactic acid is cleared from the muscle into the bloodstream relatively quickly when the muscle relaxes but will accumulate if high-intensity contractions are sustained or contractions are repeated before lactate is cleared. Buffers, such as bicarbonate and glutamine, neutralize lactic acid in the blood so that the hydrogen ions are stable, but this buffering system is very ​limited in capacity. By around 10-15 seconds following the onset of high-intensity exercise, epinephrine, a central nervous system stimulant, stimulates local muscle glycogenolysisto immobilize glucose, especially in type II, fast twitch fibers which are more glycogen-rich than their type I counterparts. Some free glucose is used to continue sustaining anaerobic glycolysis until the CNS stimulation of cardiorespiratory responses is adequate to sustain oxygen-requiring pathways. Sustained exercise is supported by the cardiovascular system and a series of physiological adjustments aimed at supplying oxygen, fuel and cell messengers to the working muscle. Immediately before or at the onset of exercise, there is a rise in heart ratedue to the release of epinephrine(i.e., adrenaline) from the adrenal medulla, located on the top of the kidneys. This rise in heart rate is linear to exercise intensity until approaching maximal effort, at which point, HR will plateau even if exercise intensity continues to increase. The highest value observed at the point of fatigue is referred to as maximal HR (HRmax), which is used to set exercise training zones. HRmax is estimated using the formula: 220 - age (in years). Mean arterial blood pressureincreases immediately in the transition from rest to exercise to an extent directly related to exercise intensity. Blood pressure responses to resistance exercise, however, are significantly greater reaching up to 480/350 mmHg due to high internal pressures within the chest cavity that result from the Valsalva maneuver—a natural tendency to stop breathing while lifting, pushing or pulling a heavyweight. Exercise results in a redistribution of blood flowby the cardiovascular system away from vital organs and to active muscle tissues. Approximately 15-20% of total blood flow is directed to muscles at rest, but during maximal intensity exercise, this figure increases to 80-85%. Several mechanisms work together to redistribute blood flow during exercise: chiefly, the vasodilationof blood vessels surrounding muscles and the vasoconstriction of blood vessels elsewhere. The vasodilation of capillaries increases blood flow, the surface area for gaseous exchange of O2 and CO2, the delivery of nutrients, and the removal of metabolic waste. Due to increased muscle blood flow and enhanced local circulation, tissues are able to take up more oxygen per 100 mL of circulating blood, a value known as the arterial-mixed venous oxygen difference. This difference gradient is expanded by at least three times that of resting values during exercise to supply more oxygen. At the onset of exercise, oxygen consumption also increases proportionally with heart rate until it plateaus, at which point, ATP supply, and demand are at equilibrium. Oxygen consumption will continue to rise with increased exercise intensity until VO2max is reached. Then, oxygen consumption cannot increase as the delivery and utilization of O2 by working muscles has reached a maximal level. If intensity remains low enough, steady-state aerobic exercise As exercise duration surpasses 1-2 minutes, contributions from the oxygen pathways become more important to sustaining muscle contraction. Lower intensity contractions that recruit slow-twitch fibers, will continue with aerobic glycolysisusing local muscle glycogen and steady supply from blood glucose. Muscle glucose proceeds in aerobic glycolysis to yield Acetyl Co A, which is subsequently oxidized in the TCA cycle and oxidative phosphorylation in the electron transport chain to yield 36 ATP. As blood sugar drops, the hormone glucagon initiates the hydrolysis of stored glycogen in the liver, which will be released into general circulation to restore blood sugar levels. In longer endurance exercise when muscle and liver glycogen levels start becoming depleted, liver gluconeogenesiskicks in for continued restoration of blood sugar levels. This process uses glycogenic compounds, such as pyruvateand lactatefrom non-working muscles, and glycogenic amino acids such as glutamine and alanine to make glucose to sustain blood glucose for the brain and working muscles. Carnitine, a locally produced and stored compound, transports fatty acid into mitochondria for beta-oxidation where they are cleaved into two-carbon units of Acetyl Co-A and oxidized by the TCA cycle and ETC chain to produce 460 ATP. After 15-20 minutes of sustained low-intensity exercise, fat is immobilized from adipose stores through the action of epinephrine, which greatly contributes to muscle ATP production.

Identify at risk values for blood cholesterol levels

Fasting blood cholesterolmeasures are taken every 4-6 years, starting at age 20, or more frequently if an individual is at an increased risk for CVD or stroke. Cholesterol is measured using a blood sample that is analyzed for total cholesterol and the cholesterol fractions, called lipoproteins. Total cholesterol is calculated by adding VLDL, which is actually a measure of serum triglycerides, together with LDL, which is a product of VLDL metabolism as it circulates, and HDL levels. A healthy lipid profile is less than 200 mg/dL total cholesterol, less than 130 mg/dL LDL, and at least 60 mg/dL HDL. Another valuable cholesterol measurement is the ratio of total cholesterol to HDL, expressed as TC: HDL, which should be less than 3.5 and 3.0 for men and women, respectively. The American Diabetes Association (ADA) recommends regular screens for diabetes riskstarting at age 45, with successive tests to follow every 3 years thereafter. Fasting blood glucose, glucose tolerance, and glycated hemoglobin measures are taken to estimate the risk of prediabetes or diabetes. For those diagnosed with diabetes, while blood and urine glucose and urine ketone testing provide useful information for the day-to-day management of diabetes, these tests cannot provide a quantitative and reliable measure of glycemia over an extended period of time. Measurements of glycated proteins, primarily hemoglobin and serum proteins, A1c levels (A1c %), with a single measurement, can quantify glycemia over months, which complements day-to-day testing. According to the ADA, diabetes therapies should strive to achieve A1C measurements of less than 7%. Adenoma screensare performed every 5-10 years in patients aged 50-70 years by colonoscopy or other imaging methods, such as CT colonography. These tests examine the structure of the colon itself in search of abnormalities. Polyps found during these tests can be removed before they become cancerous. Fecal blood teststhat detect hidden, or occult, blood in the stool are also conducted during annual screens but they are less likely to detect polyps. Hidden blood in the stool is one of the least invasive measures of colon cancer. Blood vessels in larger colorectal polyps or cancers are damaged by the passage of stool which causes bleeding into the colon. Rarely is there enough bleeding to be visible so chemical and biological assays, such as the guaiac-based fecal occult blood test (gFOBT) and the fecal immunochemical test (FIT), are usually performed to detect occult blood in the stool. If these tests are positive, a colonoscopy can be performed to determine the cause of the bleeding as it could be cancer or polyps, or non-cancerous causes like ulcers, hemorrhoids, diverticulosis (i.e., tiny pouches that form at weak spots in the colon wall) or inflammatory bowel disease (i.e., colitis). Diagnostic assessments for cardiovascular diseaseinclude a number of image tests such as cardiac computed tomography (CT scan), cardiac magnetic resonance imaging (MRI), and chest x-rays that take detailed pictures of the heart and blood vessels. Coronary angiography, also known as an angiogram, is a different diagnostic procedure that uses contrast dye and x-ray pictures to look at the insides of arteries to diagnose heart diseases after chest pain, sudden cardiac arrest or abnormal results from heart tests like EKGs or a stress tests. A stress test is another type of diagnostic assessment which imposes physical stress by exercise (or medicine if exercise is not possible), and then monitors the heart's electrical activity and rate, and whether its rhythm is steady or irregular.

Identify dietary factors in each food group that contribute to disease risk, onset and progression

Foods that accommodate changes in taste acuity may be needed to maintain a healthy daily diet in those with cancer. The essence of meats, especially chicken and fish, can be changed by soaking them in marinades, fruit juices, wine or even salad dressings. Extra flavor can also be added with a variety of strong-flavored foods. For instance, adding a small amount of bacon, garlic or onions, or chopped basil, oregano or rosemary to vegetables and meats can enhance their taste and aroma profiles. Adding tart spreads such as orange marmalade or lemon custard may taste good to patients with impaired taste sensitivity but should be consumed cautiously by those with sore mouths or throats. Foods for dry mouthshould be sweet and tart, like lemonade, to trigger the salivary glands. Chewing gum, hard candy, popsicles, and ice chips can help dry mouth during non-meal periods. Meals should be easy to swallow like soft soups and cooked and pureed fruits and vegetables. Foods can be moistened to ease swallowing with sauce, gravy or salad dressing. Beer, wine or any type of alcohol beverage exacerbates dry mouth and, thus, should be avoided, as should foods that are very dry, hard or crunchy. Eating with nausea, diarrhea, and vomiting should emphasize clear liquids (such as water or bouillon) and electrolytes. Some cancer treatments can increase susceptibility to infection. To avoid infection, hot foods should be kept hot, and cold foods must be kept cold. Raw fruits and vegetables including those with rough exteriors, like melons, should be scrubbed completely before consumption. Foods that are difficult to wash thoroughly, like raspberries, should be avoided entirely. Hands, knives, and countertops should be washed before and after handling foods, especially raw animal meats. Raw chicken, turkey, and fish should be thawed in the refrigerator or defrosted in the microwave, and all meats and eggs should be cooked thoroughly before serving. To reduce the chances of hand-to-hand food contamination, cancer patients are encouraged to steer clear of foods from bulk bins, buffets, salad bars, and self-service restaurants.

Match a phytochemical compound to a food or food pigment (i.e., color)

Fruits and vegetablesare among the most nutrient-dense foods in the diet. They are a rich source of fiber, minerals, anti-oxidant vitamins and phytochemicals. The purpose of the National Cancer Institute's program, "fruits & veggies - more matters®," is to increase fruit and vegetable consumption in the US to a minimum of five servings daily. Fruits and vegetables are the main sources of fiber in the US diet. The fruits and vegetables that are highest in fiber are apples and berries (e.g., blueberries, blackberries, and strawberries); dried fruits like prunes, apricots, dates, and raisins; and vegetables such as broccoli, Brussels sprouts, cabbage, green leafy vegetables (e.g., spinach, lettuce, kale, and collard greens) and potatoes with skins. Theantioxidant capacity of plant foods and compounds is quantified by the oxygen radical absorbance capacity unit, or "ORAC score." To maximize the antioxidant power or ORAC potential of fruits and vegetables, items from the entire color spectrum should be included in the daily diet. Of the top 20 most antioxidant-rich fruits and vegetables, 7 are red. The "red group" foods are a great source of carotenoids (i.e., provitamin A), anthocyanins, betacyanins, and lycopene. The "orange-yellow group" includes vegetables such as carrots, sweet potatoes, yellow potatoes, pumpkins, squash and yellow peppers, and fruits like oranges, tangerines, grapefruit, mangoes, cantaloupe, apricots, and bananas. The "blue-purple group" foods are great sources of anthocyanins and resveratrol, which is found in the skin of grapes consumed in purple grape juice and red wine. The "white group" foods such as garlic and onions offer significant amounts of allicin, indoles, and allyl sulfides. The "green group" foods are an important source of lutein and zeaxanthin which are technically yellow-orange pigments that are masked by chlorophyll in green foods.

Recognize nutrients that support immune function and neural development during childhood

Immune functiongradually increases from birth through childhood. It peaks in adulthood where it remains steady until a gradual decline back to birth levels in the mid-to-late forties. Susceptibility to illness, cancers, and disease is high in young children, and then lowest throughout childhood and young adulthood. Nutrition promotes maximum immune function at each stage of life by providing proteins and energy for immune cell production and for preventing catabolism and inflammation. The central nervous system grows most rapidly in the first three years of life. Long-chain polyunsaturated fatty acids, such as omega 3 or its metabolic intermediate, DHA, found in breast milk and infant formula are important for the neurological development of an infant. The myelin sheath tissue that insulates and surrounds the nerve fibers is made of lipids, cholesterol, and proteins. This sheath acts as a conduit in an electrical system, allowing rapid and efficient transmission of nerve impulses. Although myelination primarily occurs during fetal development and early infancy, it continues through childhood and adolescence. Because vitamins folate, B12, and B6 enable trans-methylation and isomerization reactions inside oligodendrocytes (i.e., nerve cells), it is essential these nutrients are adequate for the metabolism of necessary components of the myelin sheath.

Explain how the infant growth charts are used to assess childhood growth Describe sarcopenia Explain changes in bone mass changes with aging

In older infantsand young children, linear monitoring of the changes in height and weight are important anthropometric indices of growth. Children in the lowest percentiles of weight for age are clinically termed as "wasting," and those with heights in the lowest percentiles are termed "stunting." Since growth is dynamic, repeated measures over time are necessary to make these diagnoses. Excess energy intake and excess body weight cause similar risks for metabolic perturbations that lead to disease and early morbidity as undernutrition. A commonly used measure of excess body weight in children is the Body Mass Index. BMI is calculated for children the same way as it is for adults, but the results are interpreted differently depending on age and gender. BMI for age is the indicator of the relative position of the child's BMI value among children of the same age and gender. In children, the BMI percentiles include: underweight (<5th percentile), healthy weight (5th to 85th percentile), overweight (85th to 95th percentile), and obesity (≥95th percentile).

Explain the metabolic abnormalities that under pin chronic disease onset

Inappropriate food choices and unhealthy body weight promote diseaseby eliciting cell stress that could otherwise be avoided. Diet-induced cell stress stems primarily from an exacerbated level of oxygen radicals, or reactive oxygen species, that are commonly known as "free radicals." Cardiovascular disease(CVD) is a culmination of dysfunctional factors in the endothelial tissues of the heart and circulatory system that may, over time, lead to myocardial infarctionor heart attack. The process begins with an accumulation of fat in the inner surface of blood vessels that is oxidized by free-radicals. Over time, oxidative damage in the endothelium results in insufficient nitric oxide (NO) production and declining control of vascular tone and blood flow. Endothelial integrity is further compromised by vascular inflammation, consequential cell adhesion, aggregation responses and the proliferation of vascular smooth muscle cells, which eventually leads toatheroscleroticlesions. Canceris a disease that is characterized by uncontrolled cell division that leads to the growth of abnormal tissues, or tumors. Benign tumorsdo not spread or invade tissues, and they are rarely a threat to life. Malignant tumors, however, can invade organs, spread to distant locations and can be life-threatening. The DNA mutationsthat initiate and promote the growth of cancer tumors are likely caused by genetic factors and exposure to environmental carcinogensthat exacerbate cellular or tissue stress by oxidative stress and free radical activity. And while several possible cancer-causing carcinogens are consumed directly in low amounts in the regular daily diet, the progression and metastasis of cancers with etiological roots including obesity, insulin resistance, and endothelial dysfunctionare more the focus of nutrition-related research regarding cancer. Visceral adiposityexacerbates insulin resistance through a perpetuated immune response involving cytokines that interfere with insulin signaling. Insulin resistance, or insensitivity, causes the conditions hyperglycemiaand hyperinsulinemia. Chronically higher postprandial blood glucose concentration and excessive insulin secretion may contribute to the loss of the insulin-secreting function by pancreatic β-cells and lead to irreversible type 2 diabetes mellitus, another prevalent metabolic disease. Dyslipidemia, a condition characterized by abnormal levels of serum cholesterol and lipoproteins, often follows insulin resistance as a result of increased hepatic cholesterol production from excess sugars and suppressed cholesterol clearance. Dyslipidemic and hyperglycemic conditions, together, in the endothelial lining, initiates the release of inflammatory cytokines that diminish endothelial relaxation, which leads to hypertension.

Identify the nutrients involved in lipid- lowering

Individuals adhering to plant-based diets high in monounsaturated oils, like the Mediterranean diet, have consistently lower incidences of cardiovascular disease than others following a typical western diet comprised of higher levels of saturated fats. Replacing saturates with monounsaturates as the primary dietary fat source improves the blood lipid profilechiefly through a reduction in LDL cholesterol levels. Low glycemic index (GI) diets that are also high in fiber can yield significant reductions in total cholesterol and LDL-cholesterol levels. People who are insulin resistant and have type 2 diabetes have benefitted from increased fiber intake from foods and viscous fiber supplements as they tend to improve markers of glycemic control and serum lipid profiles. High fiber diets (>20 g/1,000 kcal) and diets high in soluble fiber from flaxseeds, oats and beans have also been shown to modulate total and LDL-cholesterol favorably. The low glycemic foods may reduce serum cholesterol through a reduction in the expression of the gene coding for HMG-CoA reductase, the rate-limiting enzyme in cholesterol synthesis. Diets rich in these foods also provide folate, which can help to maintainhealthy homocysteinelevels. Certain flavonoidsare associated with modest reductions in cardiovascular risk. For example, green tea catechins, mainly EGCG, have been linked with a reduced cholesterol-to-HDL ratio, which many believe is a stronger predictor of cardiovascular risk than LDL alone. Cocoais a source of flavan-3-ols that may provide cardiovascular benefits including improvements in lipoprotein profile, yielding higher HDL-cholesterol and lower total and LDL-cholesterol levels. Consuming berries or juices rich in anthocyaninsmay also generate reduced levels of LDL-cholesterol and improved cholesterol clearance via the HDL-mediated reverse cholesterol transport system.

Identify the nutrients that are more and less likely to elicit toxicity or deficiency symptoms during pregnancy

Iron deficiency anemiaduring the first two trimesters of pregnancy increases the risk for preterm labor by as much as 400%. Elevated blood homocysteineconcentrations, considered an indicator of functional vitamin B12and folate deficiencies, have also been associated with increased risk of premature delivery, as has low zinc intake (6mg/d or less) in zinc-deficientwomen. Preterm delivery is actually less common when maternal diet is adequate in calcium, magnesium and vitamin C. Neural Tube Defects (NTD) are a devastating outcome of low folateintake during pregnancy. Low maternal serum folate levels, defined as less than 4 nmol/L, can lead to megaloblastic marrow changes in mother and neural tube defects in the fetus. NTDs occur between 21 to 27 days after conception; thus, maternal folate status during this period is critical. It can prevent devastating birth defects like anencephaly or spina bifida. Inadequate folate status may also be linked to other birth defects including, among others, cleft lip, cleft palate, and limb malformations. Low serum levels of vitamin B12 during pregnancy have also been linked to NTD, a notion particularly important for vegans and vegetarians who supplement folate in early pregnancy. The fact that folate can mask vitamin B12 deficiency in routine clinical tests, is one another justification for including vitamin B12 in the prenatal supplement line up. Iodine deficiencyassociated with pregnancy is widely considered as the most common cause of preventable fetal brain damagein the world. If the maternal diet is iodine-deficient, the size of her thyroid gland enlarges by about 25%. If inadequate production of thyroid hormone continues into week ten, irreversible damage to fetal brain tissues can occur. Severe maternal iodine deficiency is also associated with an increased incidence of miscarriage and congenital hyperthyroidism — a condition that can lead to cretinism in one of two forms. The neurologic form of cretinism is characterized by mental and physical retardation and deafness; it results from maternal iodine deficiency that affects the fetus before its own thyroid is functional. The myxedematous or hypothyroid form of cretinism is characterized by short stature and mental retardation. Consuming supplemental iodine prior to conception and early in pregnancy before the tenth week of gestation effectively reduces rates of cretinism and improves neurocognitive outcomes. Iodine-deficient women who are lactating may not be able to provide sufficient iodine to their infants who are particularly vulnerable to the effects of iodine deficiency. Prenatal supplements and some multivitamin/mineral supplements on the market in the US do not contain iodine, presumably because manufacturers assume that women receive sufficient iodine through iodized salt and other food sources. However, a daily supplement providing 150 μg of iodine can help to ensure that US breast-feeding women consume sufficient iodine during these critical periods. Population-based research provides evidence that problematic maternal metabolism may be associated with less apparent neurodevelopmental problemsthat present later on, including autism and other types of learning and social developmental delays. Maternal vitamin B12deficiency can also negatively affect infant growth and development during lactation. Vegan mothers who have untreated pernicious anemia from vitamin B12deficiency may produce milk with inadequate B12 levels, which can impair fetal brain development and cause neurological problems. Vitamin B12 deficiency that results from pernicious anemia can easily be corrected with daily supplementation or with monthly intramuscular injections of the vitamin.

Recognize foods in each food group that restrict nutrients for weight loss

Low energy density foodsprovide between 0.6 to 1.5 kcal/g, or less than 300 calories per pound. Energy density is calculated by comparing water, fiber and fat content. Foods high in fiber and water are less energy-dense and vice versa. Fruits and vegetables, for this reason, are notoriously low in energy as they are high in fiber and water and completely fat-free. Low-fat dairy products like milk and yogurt are even higher in water and, although entirely devoid of fiber, they still yield an energy density of 0.78 kcal/g. Entrées comprised of foods with low energy density can reduce the number of calories by as much as 200-400 calories per serving. For instance, adding extra vegetables such as chopped spinach, shredded carrots, diced green pepper, shredded zucchini, broccoli, or mushrooms to energy-dense hot dishes like omelets, lasagna, pizza, and chili increase the food volume, reduce meal period energy intake, and increase the nutrient content of the meals substantially. This concept is commonly referred to as volumetrics, which is a weight-loss strategy that endorses calorie control through consuming foods low in energy density and high in volume so that larger portions can be consumed and thereby increase satiety. The energy density of meals and entrées can also be reduced by using lower fatingredients. For instance, using skim dairy over whole dairy in a recipe will still deliver the same amount of protein and calcium but with a fraction of the fat in the final product. Tested butter and oil substitutions for use in recipes, such as yogurt, applesauce, and sweet potato puree can also be used to reduce fat in meals, with minimal effects on palatability, yet a major impact on calorie consumption. Fat-free and reduced-fat sweets and desserts, however, are rarely superior for dieting compared to their regular fat alternatives, since the starch texturizers that are used in creamy products to mimic the mouthfeel of fat in products like coffee creamer, ice cream and yogurt are converted to fat in the body. Another dieting strategy champions the selection of foods that more quickly elicit feelings of satiety. A variety of food characteristics can promote satiation including volume, palatability, and the amount and type of dietary fiber present in foods if any. Soluble swelling and gelatinizing fibers found in boiled white potatoes, pasta, oats, and raw apples accelerate feelings of fullness. Satiety is also enhanced by liquid foods such as porridge, soups and blended high fiber fruit smoothies. Protein exhibits the most pronounced effect on satiety of the three macronutrients, with high protein beans and legumes, egg whites and Greek yogurt ranking highest in evoking feelings of fullness. One of the successes attributed to low carbohydrate diets is, in fact, increased satiety sensed from the increase in protein intake despite a general caloric deficit. Carbohydrates provide levels of satiation comparable to twice that of energy-dense fats, and when restricted in the diet, further promote appetite suppression. Unsurprisingly, highly-dissolvable and quick-digesting starchy foods such as croissants, cakes, and donuts produce low levels of satiety and increase overall consumption. Foods like these, and beverages containing sugar, that evoke modest feelings of satiety are usually also energy-dense, and should, in most instances, be restricted in a calorie-controlled diet. The energy density of a diet high in sweetened products can be improved with the use of non-nutritive sweeteners(NNS). NNS are usually effective for promoting weight loss when sizable amounts of sugar in the diet are replaced with NNS, like moving from regular to diet soft drinks. For most other artificially sweetened foods like candy, yogurts, and desserts, fewer weight loss benefits result from transitioning to sugar-free versions. Well-known NNS are often sold in single-use packets, mainly for use in beverage products. Aspartame (see, e.g., NutraSweet®) is a highly concentrated chemical that is formulated using the aromatic amino acid, phenylalanine. For the very small proportion of children born with the metabolic disorder phenylketonuria, or PKU, products that are artificially sweetened with aspartame are extremely dangerous, and therefore, phenylalanine must be listed on their packaging. Sweet 'N Low® is slightly more powerful than aspartame, requiring less to replace the taste of sucrose, but has waned in popularity of late as consumers grow more fearful of the potential carcinogenicity of its primary ingredient, saccharin. Sucralose, the main ingredient in Splenda®, is the most concentrated NNS on the market today requiring just 5 mg to replace a 15-gram portion of sucrose. Sucralose is formulated using a process in which sucrose is chlorinated, rendering the sugar indigestible making it an even more powerful weight loss tool. A slightly more natural NNS is Sweetleaf Stevia®, a non-caloric sweetener sold in powder or liquid form. It is made with stevia leaves that have been steeped to extract the active sweetening compound, rebiana, then purified, concentrated and mixed with erythritol crystals for volume. Sorbitol and mannitol are sugar alcohols that are also used in low kcal and diabetic products, as they are lower in calories per gram, and provide a slightly lower glycemic response. These products do still have an effect on blood sugar, and if overconsumed, can cause gas and diarrhea via osmosis. Low carbohydrate foodsinclude natural fats and oils, animal meat (including fish and seafood), eggs, cheese and vegetables that grow above the ground. These foods typically provide zero to five grams of carbohydrates per serving. Approximately 20% of carbohydrate calories should be from vegetable sources, with calories from meat, eggs, oils and most cheeses typically unrestricted. Besides limes and lemons, the most common fruits lowest in carbohydrates are avocados, berries, and apricots. Nuts and seeds typically provide 1.5-3 grams of carbohydrates per ounce. Low carbohydrate grains that can be integrated into later phases of carbohydrate restrictive diets include those that provide 10 grams or less per cup, such as oat bran, Carbohydrate-free beverages include coffee, tea, club soda, seltzer and, of course, water.High-proteindiets are often achieved through the consumption of conventional foods, but high-protein, portion-controlled liquid, and solid meal-replacement products can also be used. Variations of high protein diets include paleo diets, which are not restrictive of macronutrients, but by nature are high in protein.

Recall protein status based on nitrogen balance data (positive or negative)

Muscle mass gains can also be confirmed more definitively by muscle biopsies where myofibril tissues are examined, or, more commonly, by measuring urinary nitrogento determine whether nitrogen intake is higher than excretion, thereby indicating a positive nitrogen balance and protein synthesis. A negative nitrogen balance is indicative of catabolism, or muscle breakdown. Retaining too little protein or too few carbohydrate calories can have a negative impact on body composition and resistance training outcomes by inhibiting muscle and strength gains and hampering the immune system. For example, skeletal and plasma glutamine, which can be essential during times of metabolic stress, is lowered by prolonged endurance exercise. Since glutamine is critical for the optimal functioning of the immune system, a decreased plasma glutamine concentration may impair immune function and increase the risk of infection.

Identify the nutrients that are critical for muscle protein synthesis Recall the practices and dietary compounds that are related to glycogen sparing Explain how nutrition can delay fatigue during exercise and maximize recovery following exercise

Nutrition enhances physical fitness by directly supporting strength gainsthat occur as a result of myofibrillar hypertrophy, or increased myofibril size. Resistance training stimulates muscle protein synthesis (MPS) to levels exceeding breakdown for a period of up to 48 hours following exercise. Ingestion of a meal, particularly with carbohydrates, at any point during this period, will enhance muscle protein synthesis and suppress tissue breakdown. The anabolic environment after eating is created by an insulin response and is supported by amino acids and other important nutrients like chromium and vanadium, for example, which are thought to act like insulin to stimulate anabolism and amino acid uptake. These insulin-like effects also contribute to sarcoplasmic hypertrophy, which occurs as a result of increased muscle glycogen storage. While this type of hypertrophy does not contribute to the strength of the muscle, it does add considerable mass and size to myofibril tissue gained each week from resistance training. Dietary protein not only enhances myofibrillar protein gains and subsequent gains in strength but also in the production of several non-protein productsthat are needed for exercise. For instance, single amino lysine is needed to synthesize carnitine, the fat transporter; and methionine, glycine, and arginine are used to synthesize creatine, the anabolic energy buffer. Amino acids are precursors to many other critical biological compounds, including those needed for the neurotransmitters that stimulate lipolysis and fat mobilization to sustain long exercise. Even the downstream metabolites of amino acids may have a muscle-enhancing effect through protein sparing. HMB, short for beta-hydroxy-beta-methylbutyrate, is a metabolite of leucine that supplies a needed component (HMG Co-A) that is used for cholesterol synthesis within the muscle cell. Since muscle cells cannot use blood cholesterol effectively and need to manufacture it internally, especially in stressful conditions like during high-intensity exercise, additional HMB stored in the muscle may be helpful to prevent muscle cell catabolism that would otherwise be needed to accommodate the new tissue membrane synthesis. While most research does not support the notion that HMB increases muscle growth, in energy-restricted diets, such as those used to "cut weight," HMB could help spare protein tissue. Conjugated linolenic acid or CLA may have similar protein-sparing effects but, instead, through a mechanism whereby CLA, itself, is integrated into muscle membranes which are thought to inhibit the action of catabolic hormones. Iron is integrated into the protein heme as a critical oxygen-binding component needed for muscle oxygen delivery. However, before oxygen-dependent systems are effective, the anaerobic systems fuel the muscle. Recoveryof the phosphocreatine system depends on muscle creatine levels, which are provided directly from dietary sources, like animal meats and supplements, and also from the amino acids, glycine and arginine. Creatine supplementation using a dosage protocol that includes a loading phase of 20-25 grams per day for 5-7 days, then a maintenance phase of 5 grams per day, has been utilized for different types of high-power exercises that elicit maximal power output such as cycling or sprints. However, in many studies, creatine supplementation has exhibited no or minimal ergogenic effects on strength, sprint performance, and endurance exercise. Creatine supplementation may also increase fat-free mass (FFM), but the contribution from protein synthesis as compared to fluid retention (i.e., sarcoplasmic hypertrophy) is debatable. Training diets that are higher in carbohydrates can enhance carbohydrate utilization and muscle glycogen storing capacity. Glycogen stores promoteanabolic recoveryin repeated high-intensity activities like 400-meter sprints, and delay fatigueduring long-duration, glycogen-reliant exercises such as a five to ten-mile run. Carbohydrates consumed immediately before exercise will be absorbed into the blood which will spare glycogenso that, later in exercise, there is still glycogen to sustain blood glucose. Medium-chain triglycerides are water-soluble and readily absorbed into the hepatic system via the portal vein. Since they are oxidized at a similar rate as glucose during endurance exercises, MCT milks are very popular in both aerobic and anaerobic fitness markets; however, the majority of current research does not support a major ergogenic effect. Post-exercise carbohydrate intake stimulates glycogen replenishment, which may help prevent overtraining syndrome. Other natural dietary compounds that may promote muscular endurance through glycogen sparing include caffeine, which acts as a central nervous system stimulant to increase fat breakdown and utilization; and L-carnitine, a short-chained carboxylic acid that facilitates the transport of long-chain fatty acids into the mitochondria for oxidation.

Identify nutrients that can impact the rate of growing and aging of muscle and bone tissue

Nutrition promotes growth throughout childhood by providing many of the building materials and enzyme-cofactors that are needed to sustain tissue growth. Dietary amino acids cultivate muscle protein mass. Dietary fat is integrated into new cell membranes and stored in the liver and adipocytes. Dietary minerals are deposited into the elongating skeletal bones. An adequate supply of these nutrients in the childhood diet helps to ensure optimal daily weight gain. Between ages one and eight, a child's height increases by about 40%, but the velocity of change in height, as compared to infancy and puberty, is relatively low. The pre-adolescent growth spurt accounts for 20% of the full adult height, averaging a rate of two to 2.4 inches per year for boys and girls in the 9 to Puberty initiates peak growth velocitywhich spans a two-year period. Girls will gain around 17 cm of height and 15 pounds during the 12thand 13thyears; a velocity near double the period from ages 9-12, and more than four times the rate of her remaining teen years. Peak growth velocity for adolescent boys yields a 20-pound weight gain and a 17cm upsurge in height together with a much higher ratio of gained lean mass than girls. Skeletal muscle mass represents 25% of body mass for pre-pubescent boys and girls. In average boys, fat-free mass increases from 28 to 61 kg between years 10 to 18 and coincides with peak gains in height. Over the same age range, girls deposit on average 6 kg of fat, which yields a 10% gain in body fat. For boys and girls, by the end of the adolescent growth spurt, almost all of the genetically determined muscle mass has been deposited, and peak muscle massis attained. Adequate nutrient intake during adolescence is especially critical for bone elongation and attainment of peak bone mass. About 45% of the peak bone mass is attained during adolescence, and by age 17, adolescents have attained approximately 90% of their lifetime bone mass. With an adequate intake of dietary calcium, magnesium, fluoride, phosphorus, and protein and exposure to UV light from the sun, hydroxyapatite (HA) crystal formation and structure is maximized, which has a long-term positive effect on bone mineral density.

dentify dietary hazards in the pregnant and lactating diets

Pathogen: Soft Cheeses Unpasteurized Milk Products Listeria Eating Out: Street Food Buffets Sushi Order NO Sprouts Eggs Cooked throughE.coli & Salmonella Chemical: Cured Meats Nitrites Mercury Tilefish Big-eye tuna Shark Swordfish King Bad HabitsCaffeineJunk Food Nicotine Alcohol Marijuana

Describe several weight loss therapies that target the gastrointestinal tract

Physical alterations can be made to food ingredients, and now, to the gastrointestinal tract to inhibit calories from entering the body. Digestive system therapies that may help reduce energy intake in the mouthare increasing in popularity and creativity. On one end of the spectrum, extreme treatments include temporary surgical implants on the tongue that make chewing painful, and on the other, less invasive benzocaine candy, gums or mints that temporarily anesthetize the tongue and reduce taste sensation are seeking a foothold in market share. For patients who are unable to achieve a reduced energy intake voluntarily, more invasive gastrointestinal procedures are now available and becoming more commonplace. Bariatric surgeryis an option for individuals with extreme obesity (BMI ≥ 40 kg/m2), or those with a BMI ≥ 35 kg/m2in complicated by obesity-related comorbid conditions. Laparoscopic gastric banding and stomach stapling reduces stomach size and, thus, food intake. Gastric banding does not permanently alter the anatomy of the gastrointestinal tract; rather, a thin, inflatable band is placed around the top of the stomach to create a new smaller pouch to connect to the esophagus. Gastric bypass, on the other hand, permanently alters the anatomy of the gastrointestinal tract by creating a connection between the jejunum of the small intestine and a small portion of the stomach. The bypass results in reduced food digestion and absorption, which reduces the bioavailability of protein, iron, calcium and fat-soluble vitamins. Sleeve gastrectomyis a newer bariatric procedure that also permanently alters the anatomy of the stomach by removing a portion of the stomach to produce a tube-shaped stomach or "sleeve." For those who cannot lose weight on their own but are still obese, just not at life-threatening levels, medicationsmay be helpful. Medications are approved for long-term use (i.e., two years) for obese individuals with a BMI over 30, or even overweight individuals with a BMI greater than 27 who are experiencing obesity-related medical issues such as high blood pressure, high cholesterol or type 2 diabetes. Orlistat, otherwise known as prescription-based Xenical®,or in over-the-counter weight loss categories, Alli®, is a lipase inhibitor that causes dietary fat to be excreted in the stool. Nonprescription orlistat doses are estimated to be approximately 80% as effective as prescription doses of orlistat in enhancing the long-term weight loss effects in diets comprising around 30% of fat. Since orlistat is hardly absorbed, side effects are typically limited to stool-related issues including abdominal cramps, flatulence and fecal incontinence. Due to the potential loss of fat-soluble vitamins associated with its consumption, orlistat should be taken with a vitamin supplement.

Identify foods that provide nutrients for pre-exercise and mid-exercise nutrition

Pre-exercise mealsconsumed3-4 hours preceding exercise should be 300-600 calories in a carbohydrate-to-protein ratio of around 3:1. If the exercise will elicit a muscle injury response like during weight-training, protein from high-quality sources should be emphasized so that an adequate amount of essential amino acids is provided. Snacks within an hour of exerciseshould provide 25-50 grams of carbohydrates that have a low glycemic index (GI)and a moderate glycemic load (GL). Lower GI foods that are appropriate to consume before exercise, given restrictions on pre-exercise fat and fiber, include dense, complex carbohydrate sources from, among other foods, fettuccini, chickpeas, strawberries or carrots, which all have lower GIs than other foods in their respective groups. The purpose of choosing foods with a lower GI is to yield a lower total GL, which is the product of GI and carbohydrate grams per standard serving. For example, the GI of raw peeled carrots is 37, and a standard serving provides around 5 grams of carbohydrates, so the GL of carrots is (37x5) / 100 = 2.4. Low GI and GL foods are less important if carbohydrates are adequately supplied during exercise and if exercise duration is less than 30 minutes. Mid-exercise foodsshould be simple, palatable, easily digestible carbohydrates that effectively maintain blood glucose levels, while sparing glycogen, inlong-duration exercise(i.e., 90+ minutes). Since 1-1.5 cups (6-12 oz.) of water is also needed every 45-60 minutes of exercise, most athletes will refuel during exercise using fluids that provide carbohydrates. A number of solutions, like calcium-fortified orange juice diluted with water, for example, are effective pre-exercise beverages that feature a good proportion of glucose to fructose (i.e., 55:45). Honey is rich in the disaccharide sugar, isomaltulose, which provides a steady and sustained release of glucose compared to sucrose. Isomaltulose, and other variations like sucromalt, can be produced synthetically from sucrose (and maltose) for use in high-end, expensive endurance products. Typical bottled sports beverages are sweetened with maltodextrins, or shortened chains of glucose, in a solution that is 6-10% of carbohydrates by weight; an amount adequate for endurance without compromising overall taste or palatability.

Recall the symptoms, conditions and outcomes that are related to excessive and limited nutrient intake during pregnancy (gestational diabetes, eclampsia, Apgar scores factors)

Pregnancy-induced hypertensionis classified as abnormally high blood pressure (>140/90 mm Hg) that typically develops after the twentieth week of pregnancy. Nearly 1 in 10 pregnancies in the US results in gestational hypertension. If hypertension is accompanied by organ damage and edema, the clinical condition, pre-eclampsia, is diagnosed. About 5% of women with preeclampsia progress to eclampsia, a significant cause of maternal death that is characterized by life-threatening seizures and increased risk of severe bleeding. Although the specific causes of preeclampsia are not known, several vitamin and mineral deficiencies have been correlated to the condition. Low calcium status during pregnancy may influence the risk for pregnancy-induced hypertension and pre-eclampsia by stimulating the release of parathyroid hormone, thereby increasing intracellular calcium and vascular smooth muscle contractility. The increase in PTH may also stimulate the kidneys to release renin, which triggers vasoconstriction and sodium and fluid retention. Calcium supplementation during pregnancy at the daily intake (1,000 mg/day) is associated with lower risks of high blood pressure and preeclampsia. Inadequate vitamin B12 status and resulting elevated serum homocysteine concentrations are also associated with pre-eclampsia, as are intracellular deficiencies in riboflavin dependent flavoco-enzymes that are needed for nitric oxide release. Vitamin C deficiency may, through a different mechanism, similarly inhibit vasodilation and is thus associated with the progression of eclampsia.

Recall nutrient needs for pregnant and lactating women. (Focus on nutrients with higher/ lower daily quantities compared to non- pregnant women)

Pregnancy: Cumulative increase in basal energy expenditure is estimated to be approximately 30-50 thousand calories across the entire pregnancy or about 100-180 calories per day. The averaged sized fetus uses approximately 25-30 grams of maternal glucose daily in the third trimester; thus, the EAR for carbohydratesis the adult EAR plus 35 grams, or 135 grams of per day. By the third trimester, deposition for new tissues requires seven grams of protein per day. This is added to the ten grams required daily for maintenance of that new tissue, multiplied by a protein efficiency factor of .43 to derive approximately 21 grams per day. The EAR for pregnant women is 600 μg/day of dietary folate equivalents (DFEs), or 300 μg/day of synthetic folic acid on an empty stomach per day. Since folic acid is less bioavailable with food, daily intake is increased to 353 μg/day of synthetic folic acid with a meal. A daily supplement containing 400-800 μg of folic acid, in addition to consuming food folate from a varied diet, is recommended for all women planning or capable of pregnancy. Iodine requirements are increased by more than 45% during pregnancy. In the US, most diets are more than adequate in iodine, but in other countries where salt is not iodized, iodine deficiency can be problematic. Zinc requirements increase by almost 40% in pregnancy. B vitamin are all estimated to be approximately 30% higher during the second and third trimesters of pregnancy. calcium increase as a pregnancy progresses, the daily requirements for dietary calcium intake do not. The increased efficiency in intestinal absorption of calcium also will lead to increased intestinal absorption of phosphorus. Lactating: Carbohydrates must be supplied in the diet to protect maternal proteins in the production of lactose, which requires 60 additional grams of glucose per day. Proteinrequirements for lactating women are EAR plus total protein and non-protein nitrogen in their milk, or 22 to 25 grams extra per day. Like lactose, protein is adequately supplied in breast milk independent of the maternal diet and at the expense of maternal body proteins, which are only spared when dietary protein intake is at least 1.0 g/kg /day. Daily requirements for iron and folate actually decrease after giving birth, since rates of cell growth and division rapidly slow, and degrading hemoglobin mass provide a supply of stored iron. There is little variation in the requirements for water-soluble B vitamins and vitamin C in the maternal diet when transitioning from pregnancy to lactation, but the concentration of these vitamins in breast milk is reflective of the amount consumed in the maternal diet, so their importance can not be overlooked. In general, mineral levels in breast milk fluctuate less with daily intake than do vitamins because their concentrations in breast milk are more reliant on maternal body stores. Lactation requires a significant amount of water. There is no evidence to suggest that renal function and hydration status are different during lactation; thus, the daily needs for water can be estimated by milk output (.78 L) x 87% water, or .67 L/day. Using this approach, total water needs during lactation would be calculated by adding the latter amount to a non-lactating woman's AI, which totals 3.-3.6 L/day for lactating females. Increased needs for micronutrientslike potassium, chromium, choline, vitamin, pantothenic acid, and manganese are estimated similarly, that is, on the basis of the daily secretions in human milk plus the AI for women. For mothers that do not get UV light from the sun, 2,000 IU/day vitamin D supplements for the baby or maternal diet may be justified. The RDA for vitamin D for lactating women is 600 IU/day, but intake at this level in the absence of sun exposure likely results in insufficient provisions for the infant. Compensatory changes in the efficiency of absorption and retention of several minerals, like calcium,provide the additional calcium needed for lactation.

Describe the key functional (protective) features of human breast milk

Prolactin stimulates milk production Oxytocin stimulates milk ejection

Explain muscle protein synthesis and the major ways that it is affected by the aging process

Protein turnover and nitrogen balance are relatively constant across most life stages. Nitrogen accretion in newborns is higher, but by late infancy, it lowers and maintains for the rest of the life stages. Protein synthesis and deposition are also greatest during infancy, occurring at a rate of 17+ grams of protein per kg each day. After the first year, children with adequate protein status synthesize around 3 grams of protein per kg body weight per day, a rate that maintains throughout adulthood. General somatic growthis most rapid during the first 4 years, and then again from 12 to 16 years of age. During the first stage, a child typically becomes ambulatory and somatic muscle growth is slightly stimulated. The second stage follows adrenarche and the increased stimulation from gonadotrophin-releasing Hormone (GnRH) that kicks off puberty. Growth hormone activation triggers the hypothalamic-pituitary-gonadal axis to activate and enhance ovarian and testicular sex hormone secretion and secrete growth hormone. Growth factors and adequate amounts of amino acid leucine stimulate muscle protein synthesis by a mechanism known as "mTOR." mTOR is a gene inside the nucleus of cells that initiates transcription to yield cell metabolism products like enzymes and hormones and also to initiate cell growth and differentiation. During puberty, the mTOR pathways that result in cell growth and differentiation are highly sensitive to insulin receptor binding and circulating amino acid levels such that total muscle synthesis and body protein deposition exceeds tissue and protein losses which, in turn, results in muscle growth. After puberty, there is a long steady state where protein turnover is balanced, and protein synthesis and breakdown in skeletal muscle are equal unless stimulated by stress, such as resistance training. For older adults (51+ years), continual protein turnover gradually transitions from a steady state to net losses. The decline of anabolic hormones (e.g., testosterone, growth hormone, and insulin-like growth factor-I) has a catabolic effect on the musculoskeletal system known today as the "somatopause" of aging adults. By the time an adult reaches the very elderly years (75+), daily protein synthesis is reduced by more than 50% to 1 gram per kilogram of body weight per day. Impairments in muscle protein synthesis, strength, and muscle mass result from age-related changes in skeletal muscle amino acid delivery and dysfunctional mTORC1 activity.

Identify at risk values for waist circumference

Risk screening for most diseases rely on measures of anthropometry. The most common anthropometric measure is the body mass index (BMI), which assesses body weight and height. A stronger predictor of disease risk, though, specifically those related to metabolic syndrome abnormalities is waist circumference. Waist circumferences exceeding 39-43 inches for men and 39-47 inches for women are associated with greater risks for many disease types including cardiovascular disease and cancers of the esophagus, colorectal, prostate and breast tissues. Excess body fat in the visceral, or waist area is also linked with an increased risk of high blood pressure, a factor positively related to the development of kidney cancer. Waist circumferences of 31-39 inches for men and 27-35 inches for women, depending on frame size, are typically considered healthy and disease preventative.

Explain the effects of pregnancy hormones on the structure of the GI tract

Saliva acidity Risk tooth decay Gastric pressure Risk reflux B12-intrinsic factor receptor binding Calcitriol/vitamin D receptor activity Water & Electrolyte absorption Risk constipation Risk hemorrhoids

Recall nutrient intake guidelines for various weigh loss diets (Focus on calorie and macronutrient restrictions)

Since the estimated daily energy requirement (EER) is based the amount of energy that is needed for the maintenance of energy balance in a healthy adult of a defined age, gender, weight, height, and physical activity level, it follows, then, that the energy requirement for a person with excess stored fat would be less thanthat of a healthy weight adult of similar energy expenditures and height. A negative daily energy balance will elicit body weight and fat loss over time. The amount of energy to restrict daily depends on the amount of total body weight loss needed, the desired timing of weight loss, and the total daily energy expenditure (TDEE). Over time as weight is lost, if there is no change in levels of physical energy expenditures and no change in the relative proportions of lean tissue mass, then daily calorie intake must be reduced further to maintain the programmed weight loss pace. This emphasizes the importance of physical activityto help counteract the reductions in resting metabolic rate that naturally accompany calorie-restrictive diets and losses of lean body loss. The total amount of weight that should be lost is the difference between the current body weight and the ideal body weight of a similar size person. Current consensus guidelines for the management of overweight and obesity in adults recommend a weight loss of around 10% of body weight over a six-month period. Shorter-term goals typically range anywhere from one to two pounds of weight loss per week, which can be achieved in daily restrictions of 500-1000 calories below the TDEE. This amount is based on estimates of tissue loss being 75% fat and 25% lean mass, and an average estimated energy value 7.2 kcals/gram body weight lost. A very low-calorie diet(VLCD) provides around 800 kcal/day and a strict dietary structure with weighed foods and liquid shakes. VLCDs are not sufficient for long-term daily nutrient needs, but they are designed to preserve lean body mass, in that they provide 70 to 100 g protein/day. Low-calorie diets (LCD)are slightly higher in calories and range anywhere from 1,200 to 1,600 kcal/day. While providing a wider variety of food choices than the VLCD plans, diets near the 1,000-1,500 calorie range are better when at least some meals and snacks are provided or pre-portioned. Structure and energy reductions are also achieved by the use of meal replacements, including liquid shakes, high-fiber snacks, and bars. These methods minimize problematic foods and, in highly individualized plans, can even target problematic eating habits, like nighttime snacking. There are also commercial low-calorie plans that teach appropriate portions using "point tracking" or portion identification systems. These types of programs are less expensive to start and would seemingly yield better long-term compliance than plans that temporarily providing pre-portioned foods. Low-fat dietsare inherently less energy-dense compared to typical diets because fat has twice the energy density as the other energy macronutrients. Stated another way, one gram of dietary fat contributes twice as many calories as one gram of carbohydrates or proteins. Low-fat diets that produce weight loss are typically comprised of less than 20% of fat kcals, in 1500 kcal diets for women and 1800 kcals for men. Low-carbohydrate diets, unlike low-fat diets, are not directlyenergy-centric. Instead, they focus on the physiological adjustments experienced when the body is starving, which is a notable indication of the abundance of carbohydrates throughout the history of the human species. A typical low-carb diet plan has a daily limit of 20 to 60 grams of carbohydratesso that carbohydrates generate just 80-240 calories. Newer low-carb diets advocate for achieving daily nutrient allowances through plant foods, and by replacing red meat and processed meat options with "healthy fats" (e.g., olive oil). "Eco" versions of several traditional low carb programs, like Atkins®, now include vegan and vegetarian plans that promote low-carb plant foods to satisfy 100% of daily protein needs. Ahigh-proteindiet is one that includes consumption of at least 20% of daily energy intake from protein, without regard for other macronutrient intake percentages. For weight loss, high protein diets also require an energy restriction to achieve a negative energy balance.

Explain the efficiency of mineral absorption during reproduction

The absorption efficiency for several nutrients is significantly higher during pregnancy and lactation in response to increased nutrient demands. Calcium absorption efficiency, for instance, doubles between week 12 and the end of gestation. The rate of calcium absorption grows in conjunction with increases in serum 1.25-dihydroxyvitamin D and correlates with rising rates of fetal calcium transfer in the third trimester of pregnancy. During lactation, changes in calcium absorption are independent of maternal calcium intake, but these changes subside postpartum, and absorption fluctuates with intake again on the return of ovarian function. With the return of ovarian function, intestinal calcium absorption increases as does serum 1,25(OH)2D concentration, while renal retention of calcium persists. Vitamin B12 is also absorbed in higher concentrations in pregnancy. The placenta hormone, placental lactogen, is suspected to increase in the number of intrinsic factor-B12 receptors. For iron, absorption increases with demands for red blood cell production during the second and third trimester. Like in non-pregnant and non-lactating women, iron is better absorbed on an empty stomach and in the presence of ascorbic acid. Zinc absorption increases from 27 to 71% under these conditions.

Explain how bio- electrical impedance estimates lean body mass

The effects of nutrition on strength are most evident in the enhancement of muscle mass. Lean muscle mass can be assessed by total body weight or, more specifically, by muscle diameter or size. There are also special instruments and methods that measure body conductivity and water and electrolyte content to estimate lean body mass, such as total body water-isotopic dilution, bioelectrical impedance, and total body electrical conductivity techniques.

Explain the changes in calcium metabolism during pregnancy

The thyroid hormone stimulates an approximate 20% increase in basal metabolism during pregnancy and 4-5% during lactation. In later stages of pregnancy, approximately one-half of the additional energy expenditure is attributed to the fetus, which uses around 56 calories per kilogram of body weight per day, which is just under 170 kcals per day in a 3.5 kg fetus. Glucose metabolism is increased during pregnancy and lactation as women in both conditions have a higher respiratory quotient, which is an indicator of increased carbohydrate utilization. In trimesters two and three, the placental glucose transfer rate increases up to 17-26 grams of glucose per day, which is estimated to satisfy around 70% of the average 350-gram fetal brain needs. The fetal brain can also use ketoacids, which are thought to provide the remaining 30% of fetal brain fuel needs. Bone metabolism is increased during pregnancy and lactation. Bone turnover is low in the first trimester and increases in the third when fetal calcium needs are increased. The primary source of calcium for pregnant women in the third trimester is stored maternal skeletal calcium, which changes the micro-architectural pattern and mineral content of the maternal skeleton. In preparation, far in advance of fetal calcium demands, there is a thyroid response that, in conjunction with adequate serum vitamin D, yield serum calcium increases by acting on bone tissues, the GI tract and the kidneys. During lactation, the difference between bone resorption and formation represents a net flow of calcium from bone into the extracellular fluid calcium compartment for a net bone loss of about 2 mg/day. In response, PTH is released from the pituitary and calcium absorption and renal retention are improved.

Describe the hemopoietic changes in pregnancy

The white blood cell count starts to increase during the second trimester and peaks in the third trimester to reach a count as high as 29,000 during labor - two to three times higher than the typical white blood cell count of non-pregnant women. By the latter part of the third trimester, by the action of erythropoietin in the bone marrow, red blood cell masshas expanded by nearly 30%. Iron is needed to synthesize these red blood cells. Maternal iron stores (i.e., hemosiderin) from the liver and spleen may be used to expand the red blood cell mass if dietary intake is inadequate. Despite the massive increase in heme production, there is a net 2 mg/dL reduction in total hemoglobin until the last few weeks of pregnancy.

Recall appropriate pregnancy weight gain in each trimester

Trimester 1 = 2.2 kg Trimester 2 = 7.3 kg Trimester 3 = 6.5 kg

Recall the samples that ketones can be measured

Urine testing: Urine strip indicates ketones by color. Very affordable, but not always reliable Blood testing: Glucose meter with blood test trip. Most accurate results, but expensive. Breath testing: Ketonix breath meter measures acetone (ketones) on breath. Most affordable option but not most reliable.

Explain the protective benefits of fat loss

Weight loss interventions using comprehensive plans produce, on average, 10-20% of body weight lossover 12 months Weight loss occurs in stages that come faster or slower depending on, inter alia, level of dietary restriction and diet composition. Low-carb diet platforms usually produce quicker weight losses than low-fat diets. In the longer term, however, both low-carb and low-fat, Mediterranean-type diets result in similar weight losses, but low-fat diets may be easier to maintain.

Explain the biological theories on risingoverweight and obesity

While it is generally accepted that overconsumption of food calories causes obesity, the cognitive and neurobiological controls that appropriately limit food intake are, of yet, largely unexplained. The most supported theories and etiological mechanisms are rooted inbiological, neuro-hormonal gene expression and responses. Evidence of genetic ties first surfaced in studies of identical twins who were raised separately but, in adulthood, had similar growth endpoints in height, weight, and even BMI. Familial associations in body weight homeostasis between overweight parents and children are also strong, but with these studies, there is usually less certainty in the influence of genetics over the environment. There may also be a genetic defect if the maternal dietis rich in high-fat and palatable foods. In animals, this type of maternal diet elicited an enhanced pleasure response to eating desirable foods later in mature offspring, by causing in inflammation, and impairments in dopamine signaling in the hypothalamus. Mutations in the fiber projections on the anorexic signalingPOMC neuron is also suspected to disrupt gene expression for second-order PNV neurons so that information processing within the hypothalamus that trigger appetite suppression is also impaired. The most severe form of obesity in humans results from a deficiency in the genes encoding leptin or the leptin receptor. Leptinis the fat energy storage index hormone that reports to the brain to 'stop eating' by exciting the POMC neurons. Leptin also inhibits the AgRP/NPY neurons and the expression of ARP so that the orexigenic signalingthat drives food intake is ceased. Thus, in humans with disrupted leptin-receptor deficiencies, hyperphasiais common, as the primary eating cessation mechanism is impaired. Abnormally large fat cells can exacerbate obesity by contributing to chronically high levels of circulating leptin and the desensitization of the CNS to leptin action. Estrogen deficiency can also promote feeding and weight gain in a way that mimics leptin dysfunction; thus, gender is another variant in the culminating biological factors underlying obesity. With leptin dysfunction, insulin signaling is disrupted so that glucose homeostasis fades, and insulin resistance develops. Moreover, insulin may act directly on dopaminergic neuronsof the mesolimbic reward system and modulate the reward sensation and desire for high-fat or high-sugar foods by promoting dopamine release. Interestingly, the dopaminergic response to insulin is dynamic and greater in calorie and nutrient restrictive diets than in obesogenicdiets. ​Positive energy balance in modern western society is largely a function of human behavior. Some elements of human behavior and discretion are inherently biological, of course, like a person's innate disposition, personality, and motive for intrinsic reward. However, in this discussion, behavior-driven, hedonic overeating is not biological, but rather, a product of the external interactions that take place daily in the current obesogenic environment. Epidemiological weight loss research has investigated many sociological factorsand societal changes to identify underlying themes in America's changing weight status. A number of theories, old and new, are posited to explain this change including women becoming part of the workforce, multi-cultural cuisine influxes, and even increased viewing of television, or more recently, use of computers, tablets, and other smart devices. Others focus on differences in the prevalence of obesity between regions within nations, ethnicities within regions, and neighbors with differing levels of education or income. One of the major changes to the American eating pattern in the last half-century, and a growingly accepted explanation for overconsumption, is the increasing reliance on food prepared out of the home. This notion makes perfect sense considering that meals prepared out of the home are done so by a food company with a single agenda: to sell more food. Marketing strategies that appeal to customers, such as decadent and rich tastes, product functionality (i.e., portability, speed, and convenience) customization, and portion sizes that convey a greater sense of economic value, are not typically conducive to appropriate calorie intake. The average portion sizes of restaurants and quick-service establishments are approximately three to four times larger today than 50 years ago. Soft drink portions, both in prepared and packaged food segments have also increased in size but have actually decreased in price.

Recall what sample would be collected to test for gestational diabetes

While pregnancy is characterized by a mild state of hyperglycemia, excessive weight gain can lead to gestational diabetes(GD). GDis a condition that affects about 5-10% of all pregnancies in the US. Gestational diabetes usually appears in the second or third trimester and is clinically recognized as high blood glucose. Blood glucose concentrations must be tightly controlled to prevent adverse effects on the developing fetus and the mother herself. After delivery, glucose tolerance generally reverts to normal, but these mothers are at a much higher risk of developing type 2 diabetes, even after the pre-pregnancy weight is restored.

Recall the side effects of ketosis

normal metabolic state, 1-5 mmol ketones in the blood, and using fat for energy.

Recall similarities between the digestive and absorptive capabilities of older adults and infants

nutrient digestive processesbegin in the mouth at every stage of life. At first, infants form a secure latching of the mouth to the nipple of a lactating breast to stimulate "milk letdown," and to expel milk by a repetitive tongue thrust. Around four to six months of age, the natural tongue thrust that pushes solid foods out of the mouth when first offered, also known as the "extrusion reflex," begins to fade and the infant can begin feeding on semi-solid foods. First foods are not significantly digested in the mouth of infants as the teeth have not erupted and salivary enzyme production is low. Softer, liquid or high moisture foods, however, are manipulated by the tongue and cheeks in preparation for swallow. After the teeth erupt, and the pH of saliva lessens, the mouth takes on a larger role in the digestion of food matter. Digestion takes place at a considerably higher pHin the stomach of young infants, as comparedto children and adults. Despite a higher pH, proteins from human breast milk can still form a soft curd in the stomach of an infant, and the primary milk carbohydrate, alpha-lactalbumin, will unfold. The protein in cow's milk, casein, is not as easily formed into curd and is, therefore, tougher for a newborn to digest. The minerals in dairy milk, like zinc and iron, are only 10% bioavailable compared to 50% in human milk because they are protein-bound, and protein is not as easily digested by the higher pH in the infant's stomach. lderly people with atrophic gastritis or who take medications, like antacids, can have a reduced gastric acidity similar to that of young infants. Atrophic gastritis causes a reduction in the amount of hydrochloric acidproduced by the stomach, which can impair the intestinal absorption of certain protein-bound nutrients such as iron, zinc, and magnesium. Both infants and a higher proportion of elderly people compared to adults suffer incompetence of lower esophageal sphincter, permitting a condition called "acid reflux."Older babies get acid reflux from eating while lying down, and aging people develop the condition from the wearing of the muscle over time. Many older adults are also commonly prescribed medications such as nitrates and calcium channel blockers that can relax the sphincter acutely over time. The absorptive surface area in the intestine is greatest at the infant stage of life. In the first days and weeks after birth, breast milk hormones, like epidermal growth factor (EGF), increase DNA synthesis and cell division and enhance the absorption of water and glucose. Growth factors also help the infant intestine mature by eliciting a tightening at the junctions of the intestinal epithelial cells, which protects against foreign proteins and enhances paracellular absorption.