Chapter 4 - Carbohydrates
What are some food sources for soluble fiber?
Kidney beans, split peas, lentils, chickpeas (garbanzo beans), navy beans, soybeans, apples, pears, bananas, grapes, citrus fruits (oranges and grapefruits), oat bran, oatmeal, barley, corn, carrots, white potatoes
Describe how amylase aids in digestion
Mechanical digestion breaks food into smaller pieces and mixes the carbohydrate-containing food with saliva, which contains amylase, called ptyalin. This begins the hydrolysis of starch into the simpler carbohydrate intermediary forms of dextrin and maltose.
Can fat be turned into glucose?
No: the conversion of glucose to fat is irreversible. Glucose cannot be formed again but is stored as fat and, if needed, is metabolized later as fat, although its original source was carbohydrate.
What is diabetes mellitus?
a disorder of carbohydrate metabolism characterized by hyperglycemia caused by insulin that is either ineffective or deficient. The impact of diabetes is that the energy supply of glucose keeps circulating in the bloodstream; it is not available in sufficient quantities to support the energy needs of the cells.
What is secondary lactose intolerance?
Sometimes secondary lactose intolerance occurs when a chronic gastrointestinal illness affects the intestinal tract, reducing the amount of lactase produced. Even a bout of an intestinal virus or flu can cause temporary lactose intolerance. Most of these individuals recover and are again able to digest lactose.
What are some foods that are higher on the glycemic index (70-100)
Sports drinks (70), baked potato (90), corn flakes (92)
How do the Meglitinides such as Nateflinisde and Repaglinide work?
Stimulate secretion of insulin
How do the sulfonylureas such as Acetohexamide, tolazamide, tolbutamide, and Glyburide work?
Stimulates secretion on insulin
How is GDM diagnosed?
Two or more of the following criteria: Fasting BG: ≥95 1°: ≥180 2°:≥155 3°:≥140
What are some food sources for insoluble fiber?
Whole grains, brown rice, buckwheat groats, whole wheat flour, whole-wheat pasta, oatmeal, unrefined cereals, vegetables, wheat bran, seeds, popcorn, nuts, peanut butter, leafy green vegetables such as broccoli
How is pre-diabetes defined?
a FSBG of ≥100 but ≤126
How does thyroxine affect blood glucose levels?
by enhancing intestinal absorption of glucose and releasing epinephrine
What are some symptoms of DMII?
gradual onset of polyuria and polydipsia fatigue frequent infections
What are examples of food sources of starch?
grains, legumes, and some vegetables and fruits. Grains are the best source of starch.
Where is somatostatin secreted?
hypothalamus and pancreas
What does ACTH (adrenocorticotropic hormone) do?
inhibits insulin
What does somatostatin do?
inhibits the functions of insulin and glucagon
What does insulin do?
lowers blood glucose levels by enhancing the conversion of excess glucose to glycogen through glycogenesis or to fat stored in adipose tissue. Insulin also eases the absorption of glucose into the cells so the use of glucose as energy is increased.
Describe GDM
may occur during pregnancy when blood glucose levels remain abnormally high. This form of diabetes may affect the health and development of the fetus as well as the health of the mother. Although it seems as if the pregnancy triggers the diabetic response in some women, studies show that women who develop gestational diabetes tend to develop type 2 DM later in life.
What are some health problems for which hypoglycemia may be a symptom?
overproduction of insulin by the pancreas, which excessively lowers blood glucose levels, and intestinal malabsorption of glucose or insufficient glucose storage (glycogen) in the liver.
What are some food that are low on the glycemic index (0-40)?
peanuts (14), skim milk (30), whole wheat spaghetti (30)
What are examples of soluble dietary fibers?
pectin, mucilage, psyllium seed husk, guar gum, and other related gums. Soluble fiber thickens substances
What are the early signs of DM?
polydipsia - increased thirst polyuria - increased urination polyphagia - increased hunger
What are the risks associated with uncontrolled GDM?
pregnancy-induced hypertension, premature birth, large fetus size, congenital abnormalities, future obesity, and diabetes in the infant, as well as other birth complications
What are examples of nutritive sweeteners?
refined white sugar, brown sugar, dextrose, crystalline fructose, high fructose corn syrup (HFCS), glucose, corn sweeteners, lactose, concentrated fruit juice, honey, maple syrup, molasses, and reduced energy polyols or sugar alcohols (e.g., sorbitol, mannitol, xylitol)
What can individuals do if they have a familial predisposition to DMII?
relatives can adopt preventive lifestyle behaviors as young adults, reducing the risk of developing this disorder later in life. Preventive lifestyle behaviors include exercising regularly and eating a moderate kcal, high-fiber, low-fat diet to avoid weight gain, as we grow older. Both of these behaviors also work to treat type 2 DM as well.
Where are carbohydrates broken down into monosaccharides?
small intestine - via intestinal enzymes and specific pancreatic amylase
Where are the enzymes specific for disaccharides secreted?
small intestine brush border cells
What is the endosperm layer an excellent source of?
starch, the prime energy source for the sprouting plant. It also contains protein and riboflavin but much smaller amounts of niacin, thiamine, and B6
What does glucagon do?
stimulates conversion of liver glycogen to glucose, assisting the regulation of glucose levels during the night
Where is insulin produced?
the beta cells of the islets of Langerhans
Describe type I DM
the pancreas produces insufficient amounts of insulin. Insulin must be provided through daily insulin injections to control blood glucose levels. Type 1 DM tends to occur early in life, caused by viral or autoimmune destruction of the area of the pancreas responsible for insulin production; genetic factors may also be associated with type 1 DM. This disorder is not risk related.
What levels are considered blood glucose homeostasis?
70-100mg/dL
What is a disadvantage of using sugar alcohols as a replacement?
A disadvantage of sugar alcohols is that if large quantities are consumed, they may ferment in the intestinal tract because of their slower absorption rate. This fermentation may cause gas and diarrhea.
What other disorders might have symptoms similar to hypoglycemia?
A tumor on the adrenal gland may cause excessive amounts of epinephrine to be released, or a circulatory problem may affect blood flow to the brain, thus causing the confusion, headaches, and other symptoms often associated with hypoglycemia.
What happens to fructose in the body?
After absorption from the small intestine, fructose circulates in the bloodstream. When it passes through to the liver, liver cells rearrange fructose into glucose.
In which way are all forms of sugar similar?
All forms of sugar are chemically similar; each provides kcal and most do not contain any other nutrients
What are some examples of foods with a mid-range glycemic index (40-60)?
Apple (40), Banana (50), sweet potato (50), whole grain bread (50), raisin bran cereal (60)
What are some examples of grain carbohydrate food sources?
Cereals, breads, crackers, rice, or pasta, at least half as whole grains
How do the Biguanides such as Metformin and Glucophage work?
Decreases hepatic glucose production and intestinal glucose aborption
How do the alpha-glucosidase inhibitors such as aCarbose, Precose and Glucor work?
Delays absorption of glucose from GI tract
What is nutrient displacement?
Displacement occurs when whole foods, which are minimally processed, are not eaten and are replaced by foods containing added sugars. If we eat candy, soda, and other sweet snack foods instead of a sandwich and juice for lunch, we lose a number of important nutrients.
What are some examples of milk carbohydrate food sources?
Fat-free or low fat milk, yogurt, and other milk products containing lactose
What are some examples of fruit carbohydrate food sources?
Fiber-rich fruits, most fruits especially bananas, grapes, pears, apples
What are some examples of vegetable carbohydrate food sources?
Fiber-rich vegetables, starchy vegetables such as carrots, sweet potatoes, white potatoes, peas; legumes or dry beans such as kidney beans, chickpeas, and black-eyed peas
What does GRAS stand for?
Generally recognized as safe
How does increasing dietary fiber lower blood cholesterol levels?
(1) fiber foods replace higher-fat foods, particularly those containing dietary cholesterol and saturated fats; (2) soluble fiber such as pectin (citrus fruits and apples), guar gum (legumes), and oat gum (oat bran) binds lipids and cholesterol as they move through the intestinal tract.Because fiber is not digested, neither are the bound lipids and cholesterol, which make less cholesterol and lipids available to the bloodstream.
What are some examples of 1 oz equivalents of grains?
1 mini bagel 1 small biscuit 1 regular slice bread 4 snack-size slices rye bread 5 whole wheat crackers 2 rye crispbreads 1/2 English muffin 1/2 cup cooked oatmeal 3 cups popcorn 1 cup breakfast cereal 1/2 cup cooked rice 1/2 cup cooked pasta 6" tortilla
What is the AMDR for carbohydrates?
45-65%
What is the relationship between ADHD and sugar?
None. A myth that sugar consumption by children produces hyperactivity or attention deficient/hyperactivity disorder (ADHD) continues to be perpetuated. Controlled research studies have consistently failed to support this assertion.6 More than likely, excessively active behavior is related to the occasions at which sugared foods such as cake and candy are ingested. If children regularly consume excessive amounts of refined sugar, their overall dietary intake may be nutritionally deficient, possibly resulting in altered behaviors.
What is a primary cause of lactose intolerance?
Primary lactose intolerance is caused by a genetic factor that limits the ability to produce lactase. Although small amounts of lactose can often be tolerated, the level of lactase produced cannot be enhanced.
What are some reasons for eating fewer animal-derived foods?
Production of animal-derived foods substantially affects the global environment, particularly climate change. For example, livestock production releases greenhouse gases into the atmosphere. The amount created accounts for 20% of all greenhouse gases produced. Animal-derived foods tend to be energy intensive. More energy is used to create these foods from animals than their actual food energy value. And finally, animal-derived foods tend to provide more saturated fats, dietary cholesterol, and energy than plant-based foods; these are potential risk factors for diet-related chronic disorders.
How does eating increased levels of sugar affect the teeth?
Sugar supports the growth of bacteria, which promotes the formation of plaque. Plaque leads to tooth decay. Ways to decrease the development of caries are to eat sweets at the end of meals—rather than between meals—and to monitor the quantity and frequency of sugar intake. Sticky, sugary foods are more cariogenic than sweet liquids. Optimal dental hygiene reduces plaque formation and promotes dental health.
How much sugar is acceptable?
The Dietary Reference Intake (DRI) report on carbohydrates suggests that added sugars be kept to 25% or less of energy intake on a daily basis. Less added sugar intake ensures a dietary intake that is adequate in complex carbohydrates.
How much glycogen is stored in the body?
The amount held in the muscles of an adult is 150 g (600 kcal); 90 g (360 kcal) is stored in the liver
Among which populations is primary lactose intolerance common?
The condition is common among Asian/Pacific Islanders (Asian Americans), Africans (African Americans), Hispanics (Hispanic Americans), Latinos, and Native Americans. In the United States the prevalence of lactose intolerance caused by maldigestion or low lactose levels is approximately 75% in African Americans and Native Americans, 90% in Asian/Pacific Islanders, 50% in Hispanic Americans, and least common among whites.
What is the difference between eating fruits and a donut when the sucrose is the same?
The difference, however, is that naturally occurring vitamins, minerals, and fiber available in the fruit are not available in the doughnut. The doughnut's empty kcal can replace kcal from other foods that might contain a natural sweetener and also provide vitamins, minerals, protein, complex carbohydrates, and fiber. Consumption of excessively sugared food does not support wellness goals because it probably replaces other more nutrient-dense foods.
What is glycemic index?
The ranking of foods based on the level to which a food raises blood glucose levels compared with a reference food such a 50-g glucose load or white bread containing 50 g carbohydrate.4,5 A ranking of 100 is the highest glycemic index level—that is, it raises blood glucose levels the highest.
If glycogen stores are depleted, and more glucose is needed, what else can the body use?
To compensate, ketone bodies can be used for energy. Ketone bodies are created when fatty acids are broken down for energy when sufficient carbohydrates are unavailable; this process of fat metabolism, however, is incomplete. If dietary carbohydrate continues to be insufficient, a buildup of ketones results, which causes ketosis, possibly leading to acid-base imbalances in the body.
Why is the glycemic index controversial?
because it measures individual foods, not mixed meals within which the carbohydrate effect might vary
What are examples of insoluble dietary fibers?
cellulose and hemicellulose. Lignin, considered a dietary fiber, is composed of chains of alcohol rather than carbohydrate
What is the bran layer an excellent source of?
cellulose dietary fiber and contains magnesium, riboflavin, niacin, thiamine, vitamin B6, and some protein
What is the glycemic load?
considers the total glycemic index effect of a mixed meal or dietary plan. It is calculated by the sum of the products of the glycemic index for each of the foods multiplied by the amount of carbohydrate in each food.5 Given that glycemic load accounts for the mixed consumption of foods, it measures the quantity and quality of the effect of carbohydrate on blood glucose and the resulting effect on insulin release.4
What is removed in refined flour?
germ and bran
What is lactose composed of?
glucose and galactose
What is sucrose composed of?
glucose+fructose
What is maltose composed of?
glucose+glucose
Describe type II DM
the pancreas produces some insulin, but it is ineffective and unable to meet the body's needs. Risk is related to genetic, environmental, and lifestyle factors. The risk of developing type 2 DM increases with family history, age, weight, and caloric intake. Type 2 DM is associated with advancing age, being overweight and consuming excess kcal
What is the germ layer an excellent source of?
thiamine, riboflavin, vitamin B6, vitamin E, zinc, protein, and wheat oil
What are some examples of disaccharides?
• Sucrose (glucose + fructose) • Lactose (glucose + galactose) • Maltose (glucose + glucose)
What are some examples of monosaccharides?
• glucose • fructose • galactose
What are carbohydrate food sources?
• grains • vegetables • fruits • milk • meats and beans
What are some examples of polysaccharides?
• starches • fiber
What are some ways of managing lactose intolerance?
•Experiment with different portion sizes of lactose-containing foods to determine individual levels of tolerance; small amounts up to cup consumed throughout the day can often be tolerated. •Use over-the-counter lactase-enzyme tablets when consuming dairy products (presently available as Lactaid, Lactrase, Dairy Ease, and others). •If available, purchase lactose-reduced dairy products such as milk, ice cream, and soft cheeses. •Consume foods high in nutrients found in lactose-containing foods; high-calcium foods include broccoli, eggs, kale, spinach, tofu, shrimp, canned salmon, sardines with bones, and calcium-fortified orange juice. •Consume hard cheeses (in moderate amounts because of fat content) that contain lower lactose levels such as Swiss, cheddar, Muenster, Parmesan, Monterey, and provolone. •Avoid softer cheeses (or experiment to learn level of tolerance), including ricotta, cottage cheese, mozzarella, Neufchatel, and cream cheese (see Appendix L for lactose content of foods). •Test tolerance of different brands of yogurt; lactose levels may vary according to processing variations. Generally, lactase bacteria in yogurt culture hydrolyse some of the lactose. •Consider supplementation if these dietary modifications are not achieved; consult with a nutritionist for an appropriate supplement.
What are some risk factors for developing DMII
•Family history of diabetes •Low high-density lipoprotein (HDL) cholesterol and high triglycerides •High blood pressure •History of gestational diabetes or gave birth to an infant that weighed more than 9 pounds •Minority group heritage (e.g., African Americans, Native Americans, Hispanic Americans, and Asian/Pacific Islanders are at increased risk for type 2 diabetes)
What affects the glycemic index of a food?
•The physical form such as a baked potato compared with a mashed potato •The fat and protein content in addition to carbohydrate, which slows digestion •The ripeness such as in fruits and vegetables, which increases glucose content •The fiber content, which slows digestion •The botanic variety of a food, such as the different glycemic indexes of rice species