Science of Nutrition

Water loses

obligatory water excretion 500 mL daily. loss in urine, sweat, feces, lungs as vapor. total 2,500 mls/day.

Monounsaturated and polyunsaturated fats

offer health benefits RDI 20-30% total fat. 5-10% of linoleic acid. Monounsaturated: olive, canola, peanut, safflower oil and avocados. Polyunsaturated fat: Vegetables oils (sesame, corn, sunflower) and nuts and seeds.

Vitamins

organic, essential nutrients required in small amounts by the body for health, regulate body processes that support growth and maintain life.

What are the muscular actions of digestion?

peristalsis: muscle contractions in GI tract that pushes intestinal contents along. Stomach action: mixes food with gastric juices until liquify. Segmentation: contraction of the intestines to squeeze contents allowing chyme to mix. Sphincter contractions: opens and closes periodically to allow contents and prevent reflux.

Angiotensin

powerful vasoconstrictor, raises blood pressure.

Enzymes

proteins that facilitate chemical reactions without being change in the process, protein catalyst.

Anabolism

reactions in which small molecules are put together to build larger ones. Require energy. Ex: glycerides and fatty acids are assembled into triglycerides.

Insulin

secreted by pancreas in response to blood glucose. It move glucose from blood into cells. Facilitates storage of fatty acids as fat and synthesis of cholesterol.

Resting metabolic rate (RMR)

similar to the basal metabolic rate, a measure of energy use for a person at rest in a comfortable setting, but with less stringent criteria for recent food intake and physical activity. Consequently, the RMR is slightly higher than BMR.

Protein deficiency

slowed growth, impaired brain and kidney functions, poor immunity, and inadequate nutrient absorption.

Fat soluble vitamins

Vitamin A, D, E, and K. Must enter the lymph system first then the blood, require transport proteins. Held in fatty tissues and liver until needed. most likely to reach toxic levels if consumed in excess.

Electron transport chain

the final pathway in energy metabolism that transports electron from hydrogen to oxygen and capture the energy released in the bonds of ATP, also called the respiratory chain.

Hemoglobin

the globular protein of the red blood cells that carries oxygen from the lungs to the cells throughout the body.

Osmosis

the movement of water across a membrane toward the side where the solutes are more concentrated.

Physical symptoms of starvation

Wasting, decrease heart rate, decrease respiratory rate, low temperature, impaired vision, organ failure, decrease resistance to disease. psychological system: depression, anxiety, food related dreams.

Water sources

Water itself vegetables and fruits 90% meats, cheeses 50%

Artificial fats

Zero-egergy fat replacers that are chemically synthesized to mimic the sensory and cooking qualities of naturally occurring fats but are totally or partially resistant to digestion.

Neuropeptide Y

a chemical produced in the brain that stimulate appetite, diminishes energy expenditure, and increases fat storage.

TCA cycle

a series of metabolic reactions that break down molecule of acetyl CoA to carbon dioxide and hydrogen atoms.

Olestra

a synthetic fat made from sucrose and fatty acids that provides 0 k calories per gram; also known as sucrose polyester.

Bomb calorimeter

an instrument that measure the heat energy released when foods are burned, thus providing an estimate of the potential energy of the foods.

Dehydration

water output exceed water input. First sign is thirst, weakness, exhaustion, delirium and death.

Anemia

"too little blood" is a condition in which to few RBC are present or the RBC are immature (large or too small or contain too little hgb) to carry the amount of oxygen to the tissues. folate deficiency causes macrocytic or megaloblastic anemia.

Alternative Sweeteners

- Artificial: provide no energy, sugar substitutes. - Steria: herbal sweetener, derived from a plant. used as an additive in a variety of foods and beverages. -Sugar alcohols: "sugar-free" occur naturally in fruits and vegetables, used in foods to add bulk and texture. Are metabolized by bacteria in the GI tract causing intestinal gas. Don't contribute to dental caries.

Water soluble vitamins

- B complex: thiamine, riboflavin, niacin, biotin, pantothenic acid, vitamin B6, folate, Vitamin B12 - Vitamin C Move directly into the blood and travel freely, kidney remove small excess of vitamins. must be eaten regularly.

Functions of water

- Carries nutrients and waste products throughout body - Maintains the structure of large molecules such as proteins and glycogen. - Participates in metabolic reactions. - Solvents for minerals, vitamins, amino acids, glucose and many other molecules. - Act as a lubricant and fusion around joints and inside the eyes and spinal cord and in pregnancy the amniotic sac surrounding the fetus in the womb. - Aids in the regulation of normal body temperature as the evaporation of sweat from the skin. - Maintains blood volume.

Characteristics of fat

- Firmness: vegetable oils are liquid at room temperature and animal fats are solid. - Stability: all fats become spoiled when exposed to oxygen, protection from oxidation is done by storing in a sealed air tight container. - Hydrogenation: adding hydrogen molecules protects at from oxidation.

GI hormones

- Gastrin: stimulates stomach glands to secret components of hydrochloric acid. - Secretin: released into the blood by duodenum in the pretense of chyme to stimulate pancreas to release sodium bicarbonate and juices. - Cholecystokinin (CCK): stimulates gallbladder to contract and release bile, it also stimulates pancreas to release enzymes and bicarbonate.

Polysaccharides

- Glycogen: made of many glucose molecules linked together. When blood sugars is low, body breakdown branches of glycogen for energy. - Starches: plant cells stores glucose as starches. seen in grains such as wheat, rice, root crops, yams, potatoes, and legumes. Body hydrolyses starches to glucose for its own energy purposes. - Fibers: structural parts of plants found in all plant derived food- vegetables, fruits, whole grains and legumes.

Health effects of lipids

- Heart disease: LDL accumulates in the arteries restricting blood flow, increasing blood pressure. Trans fat alter blood cholesterol raising LDL and lowering HDL. - Cancer: dietary fat may promote cancer once it has arisen. - Obesity: fat has twice more kcal/gram. High fat diets exceed calorie needs.

Health effects of proteins

- Heart disease: meats and milk also contain saturated fat, increasing risk of heart disease. - Cancer: red meats increases risk. - Osteoporosis: When protein is high, calcium excretion increases. - Weight control: protein provide satiety, calorie reduction. - Kidney disease: Protein excretion increases work of kidneys accelerating kidney deterioration on people with kidney disease.

Digestion of Carbohydrates

- Mouth- salivary enzyme amylase hydrolyses starch to shorter polysaccharide then to maltose - stomach- no carbohydrate digestion, fibers provide feeling of fullness and delays in gastric emptying. - Small intestine- pancreatic amylase continues breaking down polysaccharides to shorter glucose chains. - Large intestine- Fibers attract water, soften stool for passage. Bacteria in the GI tract ferments some fiber generating water, gas and short chain of fatty acids to use for energy.

Digestion of lipids

- Mouth: fat begins to melt with body temp, salivary glands release lipase. biggest role in infants to digest fatty acids in milk. - stomach: fat floats in a quiet stomach as a layer. In pretense of food, the stomach disperses fat into small droplets and exposes fat to gastric lipase enzyme. little digestion of fat happens in the stomach. - Small intestine: Fat triggers the release of cholecystokinin, which signals gallbladder to release bile to emulsify fat. Fat molecules are drawn into the surrounding watery fluids. Fat is fully digested was they encounter lipase enzymes.

Heath effects of high sugar intake

- Obesity and chronic diseases: high-fructose corn syrup in sweet candies, bake goods and drinks increases energy intake and body weight. Liver is busy making lipids and handling glucose becomes unbalanced. Insulin resistance develops. - Nutrient deficiencies: foods and drinks high in sugars lack vitamins and minerals causing nutrient displacement. - Dental caries: bacteria in mouth ferments sugar and produces and acid that erodes tooth enamel.

food energy values can be determined by:

- direct calorimetry: measure the amount of heat release. - indirect calorimetry: measures the amount of energy consumed

Health effects of water

- hard water: high in calcium and magnesium. - soft water: high in sodium and potassium, can lead to hypertension, displaces nutrient minerals from the site of action in the body.

Secretions involved in digestion

- saliva: initiates breakdown of carbohydrates in the mouth. - Gastric juices: water, enzymes and hydrochloric acid. Kills most bacteria that enters the stomach and prevents bacterial growth. - Pancreatic juice: sodium bicarbonate neutralizes acidic chyme in the small intestine. - Bile: produced by liver, stored and release by the gallbladder. Emulsifies fat.

Functions of intestinal cells

- specialized to absorb different nutrients - foods eaten together can enhance each other's absorption by the body. ex: vitamin C enhances the absorption of iron. - nutrient transport by crossing villi to blood stream or lymphatic system.

Anatomy of intestinal tract involved in nutrient absorption

- villi: fingerlike projections from the folds of the small intestine. - microvilli: Hairlike projections in every villi that traps nutrient particles and transport them into cells. - crypts: tubular glands that lie between villi and secret intestinal juices. - goblet cells: GI tract and lungs. Secret mucous.

Recommended intake of protein

0.8g/kg/day 10 to 35% of energy intake. athletes: 1.2 to 1.7g/kg/day.

Ketone bodies

10 days of fasten, provides fuel fro brain cells. blood pH decreases. Elevated blood ketones, excreted in the urine, breath fruity odor, decreases appetite.

Recommended intake of fiber

15g/1000 kcal. 25-35g daily

Energy values

1g carbohydrate= 4 kcal 1g fat = 9 kcal 1g protein = 4 kcal 1g alcohol = 7 kcal

Water recommendations

2 to 3 liters (8-12 cups)

Pyruvate

3-carbon compound that plays a role in energy metabolism. can be used to make glucose.

Daily recommendation of cholesterol

300mg per day.

Recommended intake of carbohydrates

45-65% of energy requirement. 225-325g. daily.

DRI for physical activity

60 min per day (moderate intensity)

Water

60% of body weight in adults and more in children. 75% of body lean tissue weight and 25% of fat.

Daily allowance of fat

65g fat (based on a 30% of 2000 cal diet) 20g saturated fat (based 10% of 2000 cal diet)

Pernicious anemia

A blood disorder that reflects a vitamin B12 deficiency caused by lack of intrinsic factor and characterized by abnormally large blood cells and immature red blood cells. other symptoms include muscle weakness, and irreversible neurological damage.

Hypothalamus

A brain center that controls activities such as maintenance of water balance. Regulation of body temperature and appetite control.

Carbonic acid

A compound that result from the combination of carbon dioxide and water of a particular importance in maintaining the body's acid base balance.

Cretinism

A congenital disease characterized by mental and physical retardation and commonly caused by maternal iodine deficiency

Peptidase

A digestive enzyme that hydrolyzes peptide bonds. Endopeptidases cleave peptide bonds within the chain to create smaller fragments, where as exopeptidases cleave bonds at the ends to release fee amino acids.

Pepsin

A gastric enzyme that hydrolyzes protein. Pepsin is secreted in an inactive form, pepsinogen, which is activated by hydrochloric acid in the stomach.

Wilson's disease

A genetic disorder of copper metabolism that creates a cooper toxicity and results in neurologic symptoms such as tremors, impair speech, inappropriate behaviors, and personality changes.

Menkes disease

A genetic disorder of copper transport that creates a copper deficiency and results in mental retardation, poor muscle tone, seizures, brittle kinky hair, and failure to thrive.

Sickle cell anemia

A hereditary form of anemia characterized by abnormal sickle or crescent shaped red blood cells. sickled cells interfere with oxygen transport and blood flow. Symptoms are precipitated by dehydration and insufficient oxygen and include hemolytic anemia (RBC burst), fever, and severe pain in the joints and abdomen.

Antidiuretic Hormone (ADH)

A hormone produced by the pituitary gland in response to dehydration (or a high sodium concentration in the blood) that stimulates the kidney to reabsorb more water and therefore to excrete less. In addition to its antidiuretic effect, ADH elevates the blood pressure and so is called a vasopressin.

Aldosterone

A hormone secreted by adrenal glands that regulates blood pressure by increasing the reabsorption of sodium and excretion of potassium.

Body mass index

A measure of a person's weight relative to height: weight (kg)/height (in)2 x 703

Leptin

A protein produced by fat cels under direction of the ob gene that decreases appetite and increases energy expenditure.

Ghrelin

A protein produced by the stomach cells that enhances appetite and decreases energy expenditure.

Biotin

AI: 30 mcg/day Functions: part of coenzyme used in energy metabolism, fat synthesis, amino acid metabolism, and glycogen synthesis. Sources: Liver, egg yolks, soybeans, fish, whole grains, produced by GI bacteria. Deficiency: Depression, lethargy, hallucinations, numb or tingling sensation in arms and legs, red scaly rash around eyes, nose and mouth, hair loss. Toxicity: none reported.

Panthotenic acid

AI: 5 mg/day Functions: part of coenzyme A, used in energy metabolism. Sources: chicken, beef, potatoes, oats, tomatoes, liver, egg yolk, broccoli, whole grains. Deficiency: Vomiting, nausea, stomach cramps, insomnia, fatigue, depression, irritability, restlessness, apathy, hypoglycemia, increased sensitivity to insulin, numbness, muscle cramps, inability to walk. Toxicity symptoms: none reported.

Vitamin B6 (Pyridoxine, Pyridoxal, Pyridoxamine)

AI: adults (19-50 yrs) 1.3 mg/day UL: adults 100mg/day Functions: part of coenzyme PLP and PMP used in amino acids and fatty acid metabolism, helps convert trytophan to niacin and to serotonin, helps make RBCs. Sources: Meats, fish, poultry, potatoes, and other starchy vegetables, legumes, non citrus fruits, fortified cereals, liver, soy products. Easily destroyed by heat. Deficiency: scaly dermatitis, anemia (small cell type), depression, confusion, convulsions. Toxicity: depression, fatigue, irritability, headaches, nerve damage causing numbness and muscle weakness, leading to inability to walk and convulsions, skin lesions.

Thiamin (Vitamin B1)

AI: men 1.2 mg/day, women 1.1mg/day Functions: part of coenzyme TPP used in energy metabolism. Sources: Whole grain, fortified, or enriched grain products, moderate amounts in all nutritious foods, pork. Deficiency: Enlarged heart, cardiac failure, muscular weakness, apathy, poor short-term memory, confusion, irritability, anorexia, weight loss. Toxicity: none.

Niacin (Vitamin B3)

AI: men 16mg/day, women 14mg/day. UL: adults 35mg/day Functions: Part of coenzymes NAD and NADP, used in energy metabolism. Sources: Milk, eggs, meat, poultry, fish, whole-grain, fortified and enriched grain products, nuts and all protein containing foods. Deficiency: diarrhea, abdominal pain, vomiting, inflamed swollen smooth bright red tongue, depression, apathy fatigue, loss of memory, headache, bilateral symmetrical rash on areas exposed to sun. Toxicity: Painful flush, hives, and rash, nausea, vomiting, liver damage, impaired glucose tolerance.

Choline

AI: men 550 mg/day, women 425 mg/day UL: adults 3500 mg/day Functions: needed for the synthesis of the neurotransmitter acetylcholine and the phospholipid lecithin. Sources: milk, liver, eggs, peanuts Deficiency: liver damage. Toxicity: body ordor, sweating, salivation, reduced growth rate, low blood pressure, liver damage.

Riboflavin (vitamin B2)

AI: men: 1.3mg/day, women: 1.1mg/day Functions: part of coenzyme FMN and FAD, use in energy metabolism. Sources: milk products (yogurt, cheese), or enriched grain products, liver. Easily destroyed by UV light and radiation. Deficiency: sore throat, darks and redness at corners of mouth, painful and smith purplish red tongue, inflammation with skin lesions covered with greasy scales. Toxicity: none reported.

Diet planning principles

Adequacy, balance, energy control, nutrient density, moderation, and variety

Obesogenic environment

All the factors surrounding a present the promote weight gain such as increase food intake, especially of unhealthy choices, and decreased physical activity.

Nonessential amino acids

Amino acids that the body can synthesize Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Tryptophan, Valine.

GI hormones that regulate food intake

Amylin, CCk, enterostatin, Ghrelin, Glucagon, Oxyntomodulin, Pancreatic polypeptide, peptide YY.

bicarbonate

An alkaline compound that is produced in all cell fluids from the dissociation of carbonic acid to help maintain the body's acid-base balance. is also secreted by pancreas as part of pancreatic juice.

Renin

An enzyme release by kidneys in response to low blood pressure that hydrolyzes the protein angiotensinogen to angiotensinogen I, which results in the reabsorbing of sodium, retaining water, increasing blood volume and BP.

Lipoprotein Lipase (LPL)

An enzyme that hydrolyzes triglycerides by passing by in the blood stream and directs their parts into the cells, where they can be metabolized or reassembled for storage.

Linoleic acid

Are essential nutrients (omega 3 and omega 6). They serve as part of cell membranes and as precursor to the longer fatty acid that makes eicosanoids. Supplied by diet in vegetable oils, seeds, nuts, fish, seafood.

Chylomicrons

Are newly made triglycerides. Along with other lipids and protein are transferred via lymphatic system into the blood stream and carried to the rest of the body for use or storage.

Celiac disease

Autoimmune, inflammation of the small intestine in response to gluten, found wheat, barley, rye, and oats. Damages villi and decreased nutrient absorption. Symptoms: abdominal pain, bloating, gas, and diarrhea, need gluten-free diet.

Trans fatty acids

Behave more like saturated fats, increases blood cholesterol and the risk of heart disease.

Hypoglycemia

Blood sugar falls below normal. Weakness, tachycardia, sweating, anxiety, hunger, trembling. causes: poorly managed diabetes, too much insulin, strenuous physical activity, inadequate food intake, or illness.

Diabetes

Blood sugar increases after a meal and remains high. Insulin is either inadequate of ineffective. Type I: pancreas fails to produce insulin. Type II: cells fail to respond to insulin.

Insuline resistance

Body cells of not responds to the large quantities of insulin that the pancreas pumps out. Most often results from obesity and it improves with weight loss.

Linking of two monosaccharides is done by

condensation

Gluconeogenesis

Breakdown of protein to glucose, when glucose from carbohydrate stores are insufficient.

Amino Acids

Building blocks of proteins. Each contains an amino group and and acid group, a hydrogen atom, and a distinctive side group, all attached to a central carbon atom.

Health risk of overweight

Cardiovascular disease, type 2 diabetes, inflammation and metabolic syndrome, cancer.

Lipid transport

Chylomicrons: cells all over the body remove triglycerides from chylomicrons so this get smaller. VLDL: lipids made by liver and chylomicrons packed with proteins and send to other parts of the body. Cells removes triglycerides so VLDL shrink and the proportion to lipids shift. VLDL becomes LDL

Glycemic Index

Classifies foods accordingly. Foods with low glycemic index improve glucose control, improves blood lipids and reduces risk of heart disease, and helps with weight management.

Metabolic syndrome

Cluster of at least three of the following risk factors: high BP, high blood glucose, high blood triglycerides, low HDL cholesterol, high waist circumference.

CoA

Coenzyme A, derived from the B vitamin pantothenic acid and central to energy metabolism

Coenzymes

Complex organic molecules that work with enzymes to facilitate enzyme's activity. Vitamin B is part of their structure.

Proteins

Compounds composed of carbon, hydrogen, oxygen, nitrogen atoms, arranged into amino acids linked in a chain. some amino acids also contain sulfur atoms

buffers

Compounds that keep a solution's pH constant when acids or bases are added.

Sterols

Compounds with multiple ring structure, most famous is cholesterol. derived from foods and plants- meat, eggs, seafood, poultry and dairy. Plant sterols interfere with cholesterol absorption, lowering cholesterol levels. Some foods are fortified with sterols: margarine. Body compounds are sterols: bile acids, sex hormones (testosterone), adrenal hormones (cortisol), vitamin D and cholesterol. Liver makes 800 to 1500mg of cholesterol per day.

Health risk of alcohol

dehydration, malnutrition, inability of liver to retain vitamin B and folate, vit B deficiency, malnutrition. Wernicke-kosakoff syndrome: thiamin deficiency, paralysis of eye muscles, poor muscle coordination, impaired memory, nerve damage

Resistant Starches

dietary fibers, escape digestion and absorption in the small intestine. Common in mill grains, legumes, just ripened bananas, cooked potatoes, pasta, rice that have been chilled. Supports healthy colon.

Protein digestion and absorption

digestion is facilitated mostly by the stomach acid and enzymes, which first denature dietary proteins, then cleave them into smaller polypeptides and split them further to single amino acids. Then carriers in the membranes of intestinal cells transport the amino acids into the cells, where they are released into the blood stream.

Safe rate for weight loss

half to 2 lbs. per week (0.2 to 0.9 kg) 10% of body weight in 6 months.

Keshan disease

heart disease associated with selenium deficiency, characterized by heart enlargement and insufficiency; fibrous tissue replaces the muscle tissue that normally composes the middle layer of the walls of the heart.

Breaking disaccharides during digestion is done by

hydrolysis

Fibers

Differs from starches due to bond not able to be broken down by digestive enzymes. - Soluble fibers: dissolve in water, protect from heart disease and diabetes. - fermentable: easily digested by bacteria in the colon. found in oats, barley, legumes, and citrus fruits. - Insoluble fibers: don't dissolve in water, found in whole grains and vegetables. Promote bowel movements, alleviate constipation, and prevents diverticular disease. - Functional fibers: extracted from plants and added to foods and supplements.

Intestinal ischemia

Diminished abdominal flow to the intestine, characterized by abdominal pain, forceful bowel movements, and blood in stool.

Peptic ulcer

is a lesion in the lining of the stomach, duodenum or small intestine, can cause GI bleeding leading to iron deficiency. Ulcer that perforate the GI lining poses a life threatening complications. Causes: bacterial infection (helicobacter pylori), uses of NSAIDs, and disorders that causes excessive gastric acid secretion. ulcers can lead to stomach cancer.

Aggressive treatment for obesity

Drugs, surgeries such as liposuction, gastric bypass and gastric banding.

Recommended sugar intake

less than 10% of total energy. Most people in a 2000 calorie diet consumed approximately 25% of sugar, which equals 40 ounces of cola, 1 cup of honey, 125 jelly beans, 23 marshmallows, or 30 tsp of sugar.

Adenosine triphosphate (ATP)

Energy released during the break down glucose, glycerol, fatty acid and amino acids. ATP provides energy that peers activities in all living cells.

Proteases

Enzyme that hydrolyze protein

Major minerals

Essential mineral nutrients the human body requires in relatively large amounts (greater than 100 mg/day) macrominerals. Sodium, chloride, potassium, calcium, phosphorus, magnesium, sulfate.

Trace minerals

Essential mineral nutrients the human body requires in relatively small amount (less than 100 mg/day) micro minerals. iron, zinc, iodine, selenium, copper, manganese, fluoride, chromium, molybdenum.

Water intoxication

Excessive water intake and kidney disorder that reduces urine production. Symptoms: confusion, convulsions, and death. 10 to 20L water dilutes sodium concentration leading to hyponatremia.

Dangerous interventions for weight loss

Fad diets- popular eating plans that promises quick weight loss, may limit certain food or overemphasize others. Weight loss products- dietary supplements, natural herbal products. Some contain chemicals that can cause seizures or heart attack. other gimmicks- hot baths, steam and sauna, brushes, sponges, wraps, creams and massages that don't speed up metabolism, melt, burn or break up fat.

Ketone bodies

Fat is broken down for energy during starvation. These can accumulate in blood causing ketosis. Mainly acidic disturbing acid-base balance.

Feasting- excess energy

Favors fat formation. Excess protein: amino acids are deaminated and the remaining carbons are use to make fatty acids, which are store as triglycerides in adipose tissue. Excess carbohydrate: First store as glycogen, once stores are filled, excess glucose is converted to fat. Excess fat: move efficiently into body's fat stores.

Epinephrine

Fight/Flight response. Hormone works to release glucose from liver and glycogen to blood.

Intestinal gas

Flatulence. composed of nitrogen, oxygen, hydrogen, methane, and carbon dioxide. Foods rich in carbohydrates, starches, and fibers.

Chocking

Food slips into the trachea blocking air passageway. Foods that can cause chocking in children: meat, hot dogs, nuts, grapes, raw carrots, marshmallows, hard or sticky candy, gum, popcorn, peanut butter. Heimlich maneuver.

Phytic acid

Found in fiber rich foods, binds with mineral preventing their absorption. Risk for mineral deficiency.

Phospholipids

Found naturally in foods, lecithin is found in eggs, liver, soybeans, wheat germ and peanuts. roles: constituents of cell membranes, help dissolve fat soluble substance including vitamins and hormones. also act as emulsifiers in the body helping fat keep suspended to the blood and body fluids

Irritable Bowel Syndrome (IBS)

Frequent abdominal discomfort and disturbance in motility of GI tract. Intestinal contractions are stronger and longer causing gas, bloating and diarrhea or GI contractions are weaker causing constipation.

Diarrhea

Frequent loose, watery stools. can lead to fluid and salt losses. can be due to infection, food ingredients such as sorbitol or olestra, medications or GI disorders

Phosphorus

Function: Mineralization of bones and teeth, part of every cell, important in genetic material, part of phospholipids, used in energy transfer and in buffer systems that maintain acid-base balance. Deficiency: muscular weakness, bone pain. Toxicity: calcification of non skeletal tissues, particularly the kidneys. sources: all animal tissues (meat, fish, poultry, eggs, milk).

Vitamin D

Function: mineralization of bones (raises blood calcium and phosphorus by increasing absorption from digestive tract, withdrawing calcium from the bones, stimulating retention by kidneys. Deficiency: rickets (skeletal abnormalities, growth retardation), and osteomalacia. Toxicity: Calcium imbalance (calcification of soft tissues and formation of stones) Sources: Sun, fortified milk.

Vitamin E

Functions: Antioxidant (stabilization of cell membranes, regulation of oxidation reactions, protection of polyunsaturated fatty acids and vitamin A). Deficiency: Erythrocyte hemolysis, nerve damage. Toxicity: Hemorrhagic effects Sources: vegetable oils

Sulfate

Functions: As part of proteins, stabilizes their shape by forming disulfide bridges; part of the vitamins biotin and thiamin and the hormone insulin. Deficiency: none known, protein deficiency would occur first. Toxicity: would occur only if sulfur containing amino acids were eaten in excess; in animals it suppresses growth. Sources: all protein containing foods (meats, fish, eggs, milk, legumes, nuts).

Chronmium

Functions: Enhaces insulin action, may improve glucose intolerance. Deficiency: diabetes-like condition Toxicity: none reported Sources: meats (liver), whole grains, brewer's yeast

Sodium

Functions: Maintains normal fluid and electrolyte balance assists in nerve impulse transmission and muscle contraction. Deficiency: Muscle cramps, mental apathy, loss of appetite. Toxicity: edema, acute hypertension. Sources: tabel salt, soy sauce, moderate amounts in meat, milks, breads, vegetable, large amounts in processed foods.

Fluoride

Functions: Maintains the health of bones and teeth, confers decay resistance on teeth. Deficiency: susceptibility to tooth decay. Toxicity: Fluorosis (pitting and discoloration of teeth). Sources: Drinking fluoridated water, tea, and seafood.

Calcium

Functions: Mineralization of bones and teeth, also involved in muscle contraction and relaxation, nerve functioning, blood clotting and blood pressure. Deficiency: stunted growth in children, bone loss (osteoporosis) in adults. Toxicity: constipation, risk of stone formation and kidney disfunction, interference with absorption of other minerals Sources: milk and milk products, small fish (with bones), tofu, greens (bok chou, broccoli, chard), legumes.

Iodine

Functions: a component of the thyroid hormones that help to regulate growth, development and metabolic rate. Deficiency: underactive thyroid gland, goiter, mental and physical retardation (cretinism). Toxicity: underactive thyroid gland, elevated TSH, goiter Sources: iodized salt, seafood, plants grown in iodine rich soil and animals fed those plants.

Magnesium

Functions: bone mineralization, building of protein, enzyme action, normal muscle contraction, nerve impulse transmission, maintenance of teeth, and functioning of immune system. Deficiency: weakness, confusion; if extreme, convulsions, bizarre muscle weakness (eye and facial), hallucinations, and difficulty swallowing. In children, growth failure. Toxicity: from non food sources only, diarrhea, alkalosis, dehydration. Sources: nuts, legumes, whole grains, dark green vegetables, seafood, chocolate, cocoa.

Manganese

Functions: cofactor for several enzymes, bone formation. Deficiency: rare. Toxicity: nervous symptoms disorders Sources: Nuts, whole grains, leafy vegetables, tea.

Molybdenum

Functions: cofactor for several enzymes. deficiency: unknown Toxicity: none reported. Sources: legumes, cereals and nuts.

Copper

Functions: helps form hemoglobin, part of several enzymes. Deficiency: anemia, bone abnormalities. Toxicity: liver damage. Sources: Seafood, nuts, legumes, whole grains, seeds.

Potassium

Functions: maintains normal fluid and electrolyte balance, facilitates many reactions, supports cell integrity, assist in nerve impulse transmission and muscle contractions. Deficiency: irregular heart beat, muscular weakness, glucose intolerance. Toxicity: muscular weakness, vomiting, if injected into a vein, can stop the heart. Sources: meats, milks, fruits, vegetables, grains, and legumes.

Chloride

Functions: maintains normal fluid and electrolyte balance, part of hydrochloric acid found in the stomach, necessary for proper digestion. Deficiency: does not occur under normal circumstances. Toxicity: vomiting sources: table salt, soy sauce, moderate amounts in meats, milks, eggs, large amounts in processed foods.

Selenium

Functions: part of an enzyme that defends against oxidation, regulates thyroid hormone. Deficiency: associated with keshan disease. Toxicity: nail and hair brittleness and loss, fatigue, irritability, and nervous system disorders, skin rash, garlic breath odor. Sources: seafoods, organ meats, other meats, whole grains, fruits, and vegetables (depending on soil content)

Zinc

Functions: part of insulin and many enzymes, involved in making genetic material and proteins, immune reactions, transport of vitamin A, taste perception, wound healing, the making of sperm, and normal fetal development. Deficiency: Growth retardation, delayed fetal maturation, impaired immune function, hair loss, eye and skin lesions, loss of appetite. Toxicity: loss of appetite, impaired immunity, low HDL, copper and iron deficiencies. Sources: protein containing foods- red meats, fish, poultry, whole grains, fortified cereals.

Iron

Functions: part of protein hemoglobin, which carries oxygen in the blood, part of protein myoglobin in muscles, which make oxygen available for muscle contraction, necessary for energy metabolism. Deficiency: anemia- weakness, fatigue, headaches, impaired work performance, impaired immunity, pale skin, nail beds, mucous membranes and palms creases, concave nails, inability to regulate body temperature, pica. Toxicity: GI distress, iron overload- infections, fatigue, joint pain, skin pigmentation, organ damage. Sources: red meats, fish, poultry, shellfish, eggs, legumes, dried fruits.

Vitamin A

Functions: vision, maintenance of cornea, epithelial cells, mucous membranes, skin, bone and tooth growth, reproduction, immunity. Deficiency: infection diseases, night blindness, blindness (xerophthalmia), keratinization. Toxicity: reduced bone mineral density, liver abnormalities, birth defects Sources: Retinol: milk and milk products Beta-carotene: dark green, leafy and deep yellow/orange vegetables

Carbohydrate metabolism

Glucose cells as store as glycogen, when blood sugar is high. Once blood sugar drops the liver breaks down chains of glycogen to glucose to supply energy to brain and other tissues. Extra glucose in the body is broken down into smaller molecules and stores them as fat which travels to fatty tissues for storage.

Fasting- inadequate energy

Glucose from liver's stored glycogen and fatty acids from adipose tissue travels to the cells. These molecules are broken down as acetyl CoA. Liver glycogen is depleted- Blood sugar drops Starvation demands cells to degrade their component for fuel.

Monosaccharides

Glucose: blood sugars, serves as essential source Fructose: sweetest of sugars, naturally in fruits and honey. Galactose: hardly sweet, naturally in foods.

Lipid absorption

Glycerol and fatty acids diffuse easily in to the intestinal cells and are absorbed directly into the blood stream. Monoglycerides and long chain fatty acids are emulsified by bile, forming micelles- diffuse into intestinal cell where they are assembled into new triglycerides.

High density lipoprotein

HDL is made by the liver. it removes cholesterol from cells and carries it back to the liver for recycling. decreases the risk of heart disease, it has anti-inflammatory properties by keeping arteries from plague breaking apart.

Health effects of starches and fibers

Heart disease: high carbohydrate diets alters blood lipids increasing risk of heart disease. Whole grains, legumes and vegetable protects against heart attack. Foods rich in fiber lower blood cholesterol by binding with bile acids in the GI tract increasing their excretion. Diabetes: Foods with fiber help prevent type II diabetes by binding with nutrients and slowing glucose absorption. GI health: dietary fibers prevents constipation, hemorrhoids, bacteria that invades the appendix, and it stimulates the GI tract muscles to retain its strength. Cancer: fiber protects against colon cancer by diluting, binding and moving cancer causing agents from colon. Weight management: foods with fiber are low in fat and sugars. less energy per bite. Feeling of fullness

GI bacteria

Helps alleviate diarrhea, constipation, IBS, ulcers, allergies, lactose intolerance, infant colic, enhances immune function, and protects against colon cancer. it digest fiber, and produces nutrients to use as energy and small amount of vitamins.

Harmful effects of excessive fiber intake

Inability to meet energy and nutrient needs. switching to a high fiber diet can cause abdominal discomfort, gas, diarrhea, or bowel obstruction. Fiber intake must be increased gradually and drinking plenty of fluids. Fiber can also prevent the absorption of nutrients by binding with minerals.

Colitis

Inflammation of the large intestine. Severe diarrhea. Need bowel rest and medication or resection of colon and rectum.

Fat replacers

Ingredients that replace some or all of the functions of fat and may or may not provide energy

Diverticulosis

Intestinal wall develops bulges in weakened areas, commonly in colon. diverticula: bulging or pockets, diverticulitis: diverticula gets inflamed or infected. Treatment: antibiotic therapy or surgery.

Low density lipoprotein

LDL circulate throughout the body making their contents available to the cells of all tissues. cells used triglycerides, cholesterol and phospholipids to use for energy, make hormones and build new membranes. LDL receptors in liver removes excess LDL from blood circulation to control blood cholesterol.

Lactose intolerance

Lactase increase at birth and declines during childhood and adolescence to 5-10%. About 30% of people retain enough lactase to digest and absorb lactose efficiently in adult life. Undigested lactose in the intestine causes bloating, abdominal discomfort, and diarrhea. Undigested lactose becomes food for intestinal bacteria, which multiply producing irritating acid and gas. Causes: lactase decline and age, intestinal villi damage by disease, certain medicines, prolonged diarrhea or malnutrition. Prevalence: genetic component, higher amount North Americans and Southeast Asians and lower among Scandinavians and Europeans.

Low carbohydrate diets

Metabolism similar to fasting. Glycogen stores provide glucose to nerves, brain and blood. Once depleted glucose is made from amino acids. Urine production increases as glycogen and protein are broken down releasing water. ketosis. Adverse effects: nausea, fatigue, constipation, low blood pressure, increased uric acid leading to kidney disease and going inflammation, bad breath. Pregnant women: fetal harm and still birth.

Simple carbohydrates

Monosaccharides: single sugars Disaccharides: sugars composed of pairs of monosaccharides.

Absorption of Carbohydrates

Mostly absorbed in the mouth, nutrient absorption takes place in the small intestine. Glucose and galactose enter intestinal cells by active transport and fructose by diffusion. Fructose and galactose are metabolize in the liver, while glucose is sent out to body cells for energy.

Conjugated linoleic acids

Naturally occurring trans fatty acids. May even have health benefits (omega 3 and 6), help regulate blood pressure, blood clotting, and other functions.

Pellagra

Niacin deficiency disease. Diarrhea, Dermatitis, Dementia, Death.

weight management

maintaining body weight in a healthy range by preventing gradual weight gains over time and losing weight if overweight, and by preventing weight losses and gaining weight if underweight.

Neural tube defects

malformation of the brain, spinal cord, or both during embryonic development that often result lifelong disability or death.

Disaccharides

maltose= glucose + glucose: produced when a starch breaks down during carbohydrate digestion or during fermentation process that yields alcohol. sucrose= glucose + Fructose: table sugar refined from sugar cane and sugar beets, then granulated. Lactose= glucose + galactose: main carbohydrate of milk.

Brown adipose tissue

masses of specialized fat cells packed with pigmented mitochondria that produce heat instead of ATP.

Gastroesophageal reflux

Painful sensation behind breastbone when esophageal sphincter allows stomach contents into the esophagus. causes: overeating, thigh clothing, laying down/bending over, some medications and smoking.

Couple reactions

Pairs of chemical reactions in which some of the energy released from the breakdown of one compound is used to create a bond in the formation of another compound.

GI enzymes

Pancreas produces enzymes according to diet. If carbohydrates are mostly consumed pancreas will produce mostly carbohydrates. Enzymes are release by the pancreas in inactive form and are activated in the intestines.

Complex carbohydrates

Polysaccharides: large molecules. chains of monosaccharides.

Eicosanoids

Powerful compounds that participate in blood pressure regulation, blood clot formation and the immune response to injury and infection.

Beriberi

Prolonged thiamine deficiency- damage to nervous system characterized by muscle weakness in arms and legs. Damage to cardiovascular system- dilated blood vessels increase heart work and kidney retain sodium and water causing edema.

Vomiting

Propelling food. Body's adaptive mechanism to fit itself from something irritating. Continuous vomiting causes fluids and salts imbalances.

triglycerides

Provide cells with energy, insulate against temperature extreme, protest against shock, provide structural material for cell membranes, and participate in cell signaling pathways. Adipose cells have unlimited capacity to store fat. Accumulation of fat in non adipose cells occurs when diet deliver excess fat and liver increases its production. Fatty liver linked to obesity causes chronic inflammation leading to fibrosis, cirrhosis, and cancer. Adipose tissue secretes hormones (adipokines) proteins that help regulate energy balance and influence several body functions.

Function of lipids in the body

Provide energy, insulation, protects against shock and maintain cell membranes.

Vitamin B12 (Cobalamin)

RDA: aduls 2.4 mcg/day Functions: part of coenzyme used in new cell synthesis, helps to maintain nerve cells, reforms folate coenzyme, helps break down some fatty acids and amino acids. Sources: animal origin (meat, fish, poultry, shellfish, mild, cheese, eggs), fortified cereals. Deficiency: pernicious anemia, anemia (lg cell type), fatigue, degeneration of peripheral nerves progressing to paralysis, sore tongue, loss of appetite, constipation. Toxicity: none reported.

Folate (folic acid, folacin, pteroyglutamic acid)

RDA: aduls 400 mcg/day UL: 1000 mcg/day Functions: part of coenzyme THF and DHF, used in DNA synthesis and therefore important in cell formation. Sources: fortified grains, leafy green vegetables, legumes, seeds, liver. Easily destroyed by heat and oxygen. Deficiency: anemia (lg cell type), smooth red tongue, mental confusion, weakness, fatigue, irritability, headaches, shortness of breath, elevated homocysteine Toxicity: masks vitamin B12 deficiency symptoms.

Vitamin C (ascorbic acid)

RDA: men 90mg/day, women 75mg/day, smokers +35mg/day. UL: adults: 2000 mg/day. Functions: collagen synthesis (strengthens blood vessel walls, forms scar tissue, provides matrix for bone growth), antioxidant, thyroxin synthesis, amino acid metabolism strengthens resistance to infection, helps iron absorption. Sources: citrus fruits, cabbage type vegetables (such as brussels sprouts and cauliflower), dark green vegetables (bell peppers and broccoli), cantaloupe, strawberries, lettuce, tomatoes, potatoes, papayas, mangoes. Easily destroyed by heat and oxygen. Deficiency: Scurvy (bleeding gums, pinpoint hemorrhages, abnormal bone growth, and joint pain) Toxicity: diarrhea, GI distress.

Catabolism

Reaction in which large molecules are broken down to smaller one. release energy. Ex: glycogen to glucose, proteins to amino acids.

Glycemic response

Refers to how quickly glucose is absorbed after a person eats. How quickly glucose rises and returns to normal.

Glucagon

Release by pancreas when blood sugar drops to signal liver to break it glycogen stores and release glucose into the blood.

Belching

Results from swallowing air by eating too fast, ill fitting dentures, carbonated beverages and chewing gum.

Fatty acid deficiencies

Seen in infants and young children who consume fat free milk and hospital patients mistakenly fed formulas without polyunsaturated fatty acids. Deficiencies include growth retardation, reproductive failure, skin lesions, kidney and liver disorders, subtle neurological and visual problems.

Constipation

Straining, hard stool and infrequent bowel movements less than three times per week. Abdominal discomfort, headache, backache, gas. Causes: medication, lifestyle, medical problems such as bowel obstruction. Increase fiber, fluids and exercise. Complications: diverticulosis.

Roles of Proteins

Structural materials- collagen, enzymes, hormones, regulators of fluid balance, acid base regulators, transporters, antibodies, source of energy and glucose.

Vitamin K

Synthesis of blood-clotting proteins and bone proteins Deficiency: hemorrhage. Toxicity: none known. Sources: Synthesized in the body by GI bacteria; dark green, leafy vegetables.

Osmotic pressure

The amount of pressure needed to prevent the movement of water across and membrane.

glycerol and fatty acids to glucose

The body can convert the small glycerol portion of a triglyceride to either pyruvate (and then glucose) or acetyl CoA. The fatty acids of triglyceride, on the other hand, cannot make glucose, but they can provide abundant acetyl CoA. Acetyl CoA may enter the TCA cycle to release energy or combine with other molecules of acetyl CoA to make body fat.

amino acids to glucose

The body can use some amino acids to make glucose, where as others can be used either to provide energy or to make fat. Before an amino acid enters any of these metabolic pathways, its nitrogen-containing amino group must be removed through deamination.

Essential amino acids

The body cannot synthesize in amount sufficient to meet physiological needs. Alanine, Arginine, Asparagine, Aspartic acid, Cysteine, Glutamic acid, Glutamine, Glycine, Proline, Serine, Tyrosine.

Denaturation

The change in a protein shape and consequent loss of its function brought about by heat, agitation, acid, base, alcohol, heavy metals, or other agents.

Basal metabolism

The energy needed to maintain life when a body is at complete digestive, physical and emotional rest.

Satiety

The feeling of fullness and satisfaction that occurs after a meal and inhibits eating until the next meal. Satiety determines how much time passes between meals.

Satiation

The feeling of satisfaction and fullness that occurs during a meal and halts eating. Satiation determines how much food is consumed during a meal.

Thermogenesis

The generation of of heat, used in physiology and nutrition studies as an index of how much energy the body is expending.

Glucose to glucose

The glucose to energy pathway begins with glycolysis, pyruvate may be converted to lactate anaerobically or to acetyl CoA aerobically. The pathway from pyruvate to acetyl CoA is irreversible. Once the commitment to acetyl CoA is made, glucose is not retrievable. Glucose can be synthesized only from pyruvate or compounds earlier in the pathway.

Energy balance

The k calories consumed from foods and beverages compared with the energy expended through metabolic processes and physical activities.

Glycolysis

The metabolic breakdown of glucose to pyruvate. does not require oxygen.

Physiological fuel value

The number of k calories that the body derives from food, in contrast to the number of k calories determined by calorimetry.

Set-point theory

The point at which controls are set, like a thermostat but it relates to body weight. Proposes that the body tends to maintain a certain weight by mean of its own internal controls.

Transcription

The process of messenger RNA being made from template of DNA.

Translation

The process of messenger RNA directing the sequence of amino acids and synthesis of proteins.

Basal metabolic rate (BMR)

The rate of energy use for metabolism under specified conditions: after a 12 hr fast and restful sleep, without any physical activity or emotional excitement, and in a comfortable setting. It is usually expressed as k-calories per kilogram body weight per hour.

Metabolism

The sum total of all the chemical reactions that go on in living cells. Energy metabolism includes all the reactions by which the body obtains and expends the energy from food.

Blood lipid profile

Total cholesterol: >200mg/dL LDL: <100mg/dL HDL: > 60mg/dL Triglycerides: < 150mg/dL