Carbohydrates chapter 2

Take steps to avoid dental caries

Choose between-meal snacks that are healthy and teeth-friendly. Limit between-meal carbohydrate. Avoid high-sugar items. Brush promptly after eating. Chew gum sweetened with sugar alcohols. Use fluoridated toothpaste.

Polysaccharides

Complex carbohydrates Do not taste sweet Starch, glycogen, and fiber are types of polysaccharides.

Lactose or "milk sugar"

Composed of glucose and galactose Found naturally in milk What does it do? Least sweet of all sugars

Maltose

Composed of two joined glucose molecules Not found naturally in foods

Whole grains

Consist of the entire kernel of a grain Can be cracked, ground, or milled into flour Composed of three parts The bran The endosperm The germ (embryo)

Digestion

Cooked starch begins to undergo digestion in the mouth by the action of salivary amylase. Most carbohydrate digestion occurs in the small intestine. Disaccharidase enzymes split disaccharides into monosaccharides. Monosaccharides are the only form of carbohydrates the body is able to absorb intact. Normally, 95% of starch is digested usually within 1 to 4 hours after eating.

WAYS TO LIMIT ADDED SUGARS

Cut Back or Eliminate Sugar-Sweetened BeveragesRely on Natural Sugars in Fruit to Satisfy a "Sweet Tooth" Limit Sweetened Grain-Based and Dairy-Based Desserts and Candy Cut Sugar in Home-Baked Products, if Possible Read Labels natural sugars contain little or no milk or fruit, Natural and added sugars

Glycemic load

More accurately define a food's impact on blood glucose levels Not reliable for choosing healthy diet a food's glycemic index multiplied by the amount of carbo

Limit added sugars

Sugar adds flavor and interest. Inaccurately blamed for a variety of health problems Limiting intake is prudent. Sugar alternatives Sugar alcohols Nonnutritive sweeteners

Absorption

Sugars are absorbed through intestinal mucosa cells. Undigested starch passes with stools. Fibers may impair the absorption of some minerals—namely, calcium, zinc, and iron—by binding with them in the small intestine.

Total carbohydrate

The RDA for carbohydrates is set at 130 g for both adults and children. carbohydrates provide 45% to 65% of total calories consumed

Empty calories

"Extras" Carbohydrate content varies

Maximal level of

25% of total calories or less from added sugars is recommended.

Carbohydrate-Containing Compounds.

The body can convert glucose to other essential carbohydrates such as ribose, a component of ribonucleic acid (RNA) and deoxyribonucleic acid (DNA), *keratin* sulfate (in fingernails), and hyaluronic acid (found in the fluid that lubricates the joints and vitreous humor of the eyeball).

Preventing ketosis

Without adequate glucose, fat oxidation prematurely stops at the intermediate step of ketone body formation. Increased production of ketones causes nausea, fatigue, loss of appetite, and ketoacidosis. Dehydration and sodium depletion may follow.

Enrichment:

adding back certain nutrients (to specific levels) that were lost during processing.

Fortified:

adding nutrients that are not naturally present in the food or were present in insignificant amounts.

Complex carbohydrates,

also known as *polysaccharides*, are composed of hundreds to thousands of glucose molecules linked together. a group name for starch, glycogen, and fiber; composed of long chains of glucose molecules.

Glucose

also known as dextrose, is the simple sugar of greatest distinction: it circulates through the blood to provide energy for body cells; it is a component of all disaccharides and is virtually the sole constituent of complex carbohydrates; and it is the sugar to which the body converts all other digestible carbohydrates.

Carbohydrates (CHO)

are comprised of the elements carbon, hydrogen, and oxygen arranged into basic sugar molecules. They are classified as either simple sugars or complex carbohydrates (a class of energy- yielding nutrients that contain only carbon, hydrogen, and oxygen, hence the common abbreviation of CHO.)

Functional Fiber:

as proposed by the Food and Nutrition Board, functional fiber consists of extracted or isolated nondigestible carbohydrates that have beneficial physiologic effects in humans.

Dietary Fiber:

carbohydrates and lignin that are natural and intact components of plants that cannot be digested by human enzymes.

Refined Grains and Refined Flours:

consist of only the endosperm (middle part) of the grain and therefore do not contain the bran and germ portions.

Simple sugars

contain only one (mono-) or two (di-) sugar (saccharide) molecules; they vary in sweetness and sources (classification of carbohydrates that includes monosaccharides and disaccharides; commonly referred to as sugars.)

Whole Grains and Whole Grain Flours:

contain the entire grain, or seed, which includes the endosperm, bran, and germ.

Prevent Dental Caries

erodes tooth enamel "sticky." healthy and teeth friendly, such as fresh vegetables, apples, cheese, and popcorn. Limit soft drinks Avoid hard candy, suckers, and cough drops. Brush promptly after eating. educe the risk of cavities by stimulating production of saliva, rinse the teeth and neutralize plaque acids. sugar alcohols and nonnutritive sweeteners Use fluoridated toothpaste.

Gastrointestinal Function

fiber in whole grains is credited with promoting regularity by increasing stool bulk and shortening transit time.whole grains may lower oxidative stress and inflammation. fiber, antioxidant vitamins, phytochemicals, minerals, and prebiotics work synergistically to improve gastrointestinal function and help protect against disease.

Postprandial:

following a meal.

ketone body

intermediate, acidic compounds formed from the incomplete breakdown of fat when adequate glucose is not available.

milk

is considered a "protein," more of milk's calories come from carbohydrate than from protein. One cup of milk, regardless of the fat content, provides 12 g of carbs-

Soluble Fiber:

non-digestible carbohydrates that dissolve to a gummy, viscous texture. slowing gastric emptying time to promote a feeling of fullness, delaying and blunting the rise in postprandial serum glucose, and lowering serum cholesterol, whereas insoluble fiber is credited with increasing stool size to promote laxation.

Insoluble Fiber:

non-digestible carbohydrates that do not dissolve in water.

On average, Americans eat

one serving per day of whole grains. Factors contributing to the low intake of whole grains include consumers' inability to identify whole grains, a lack of awareness of their health benefits, cost, taste, and unfamiliarity with how to prepare whole grains.

Fructose

or "fruit sugar" Sweetest of all natural sugars High-fructose corn syrup (HFCS)

Glycogen:

storage form of glucose in animals and humans. is the animal (including human) version of starch; it is stored carbohydrate available for energy as needed. Liver glycogen releases glucose into the bloodstream to maintain blood sugar between meals. provide fuel for tissues. No dietary source of glycogen

Type 2 Diabetes

study found a significant decrease in type 2 diabetes risk in people in the highest quintile of whole-grain intake compared to those in the lowest, after adjusting for age and calorie intake

Monosaccharides,

such as glucose, fructose, and galactose, are absorbed "as is" without undergoing digestion single (mono) molecules of sugar (saccharide); the most common mono- saccharides in foods are hexoses that contain six carbon atoms.

disaccharides,

such as sucrose (table sugar), maltose, and lactose, must be split into their component monosaccharides before they can be absorbed. "double sugar" composed of two (di) monosaccharides

Polyols:

sugar alcohols produced from the fermentation or hydrogenation of monosaccharides or disaccharides; most originate in sucrose or glucose and maltose in starches. Sugar alcohols, are used as sweeteners but are not true sugars; they are derived from hydrogenated sugars and starches

Nonnutritive Sweeteners:

synthetically made sweeteners that provide minimal or no carbohydrate and calories; also known as artificial sweeteners.

Acceptable Daily Intake (ADI):

the estimated amount of a food additive that a person can safely consume every day over a lifetime without risk

Starch:

the storage form of glucose in plants. Grains, such as wheat, rice, corn, barley, millet, sorghum, oats, and rye, are the world's major food crops and the foundation of all diets. Starch Potatoes, dried peas and beans, and other starches

Total Fiber:

total fiber dietary fiber functional fiber.

Adequate intake (AI)

total fiber is set at 14 g/1000 calories or 25 g/day for women and 38 g/day for men Mean fiber intake among American men and women 20 years and older is 17.7 g and 14.3 g,

anabolism

using glucose to build other compounds

Cardiovascular Disease

whole grains is associated with a reduced risk of cardiovascular disease 2.5 servings/day hole grains, including fiber, antioxidants, and phytochemicals, may synergistically work to influence cholesterol levels, blood pressure, blood clotting, and insulin sensitivity.

Weight Management

whole-grain intake is associated with lower risk of obesity and weight gain

Sugar alternatives

—(cont.) Sugar alcohols Sorbitol, mannitol, and xylitol Natural sweeteners derived from monosaccharides Most are commercially synthesized. Incompletely absorbed Side effects Offer sweetness without promoting cavities

carbohydrates amounts in Vegetables

"watery" vegetables provide 5 g carbohydrate Asparagus Bean sprouts Broccoli Carrots Green beans, wax beans Okra Tomatoes "starchy" vegetables provides approximately 15 g carbohydrates:Corn Legumes (e.g., pinto beans, black beans, garbanzo beans) Lentils Peas Potatoes, sweet potatoes, yams Winter squash (e.g., acorn, butternut)

Increase Whole Grains

"whole package" of healthful components, including *essential fatty acids, antioxidants, vitamins D, E, minerals, and phytochemicals(any of various biologically active compounds found in plants that may prevent HD,cancer Gi prblems)*

TIPS FOR INCREASING WHOLE-GRAIN INTAKE

*Substitute* Whole wheat bread for white bread Brown rice for white rice Whole wheat pasta or pasta that is part whole wheat, part white flour for white pasta Whole wheat pita for white pita Whole wheat tortillas for flour tortillas Whole grain or bran cereals for refined cereals Half of the white flour in pancakes, waffles, muffins, quick breads, and cookies with whole wheat flour or oats Whole wheat bread or cracker crumbs for white crumbs as a coating or breading for meat, fish, and poultry Whole corn meal for refined corn meal in corn cakes, corn bread, and corn muffins *Add* Barley, brown rice, or bulgur to soups, stews, bread stuffing, and casseroles A handful of oats or whole-grain cereal to yogurt *Snack on* Ready-to-eat whole-grain cereal, such as shredded wheat or toasted oat cereal Whole-grain baked tortilla chips Popcorn

Total Carbohydrates

Acceptable macronutrient distribution range Fiber

Fruits

Almost all of the calories in fruit come from sugar (mostly fructose), with small amounts of starch and minute quantities of protein providing negligible calories. Exceptions to this are avocado, olives, and coconut, which get the majority of their calories from fat. Fiber is located in the skin of fruits.

Protein sparing

An adequate carbohydrate intake is especially important whenever protein needs are in- creased such as for wound healing and during pregnancy and lactation. Protein provide 4 cal/g protein Functions replenishing enzymes, hormones, antibodies, and blood cells.

Fat

Any glucose remaining at this point—after energy needs are met, glycogen stores are saturated, and other specific compounds are made—is converted by liver cells to triglycerides and stored in the body's fat tissue. The body does this by combining acetate molecules to form fatty acids, which then are combined with glycerol to make triglycerides. Although it sounds easy for excess carbohydrates to be converted to fat, it is not a primary pathway; the body prefers to make body fat from dietary fat, not carbohydrates.

Sugar: too much of a good thing

Behavioral problems in children Obesity Diabetes mellitus Heart disease

Glycogen

Body's backup supply of glucose One-third of the body's glycogen reserve is in the liver.

Galactose

Does not occur in appreciable amounts in foods Combines with glucose to form lactose

Metabolism

Fructose and galactose are converted to glucose in the liver. Liver releases glucose to maintain blood sugar level. Rise in blood sugar causes pancreas to release insulin. Postprandial state Blood glucose concentration begins to drop. Pancreas releases glucagon. Stimulates liver to release glucose

Fiber.

Generally considered a group name for polysaccharides that cannot be digested by human enzymes Commonly referred to as "roughage" Categorized as insoluble or soluble "Dietary" fiber "Functional" fiber Commonly assumed that fiber does not provide any calories Source of energy for colon lining

Sources of carbohydrates

Grains, Vegetables, Fruits, and Dairy are the MyPlate groups that provide the majority of carbohydrates. Nuts and dried peas and beans Grains Synonymous with "carbs" Classified as "whole" or "refined"

Nonessential Amino Acids.

If an adequate supply of essential amino acids is available, the body can use them and glucose to make nonessential amino acids.

Glycemic response

Increase in blood glucose levels effect a food has on the blood glucose concentration; how quickly the glucose level rises, how high it goes, and how long it takes to return to normal.

what are components os simple sugar?

Monosaccharides • glucose • fructose • galactose Disaccharides • sucrose • maltose • lactose

Dietary guidelines

Less likely to develop insulin resistance and metabolic syndrome, common precursors of type 2 diabetes Associated with improved body weight management Tips for choosing whole grains

Concentrate on fiber and whole grains

Most consistent benefit of consuming adequate fiber is to relieve or prevent constipation. Linked to a decreased risk of heart disease, cancer, diabetes, and obesity Dietary guidelines recommend that adults and children consume at least one-half of their grain servings from whole grains. Results in 20% to 30% lower risk of atherosclerotic cardiovascular disease

Cancer

Observational studies in the United States suggest a strong inverse relationship between whole- grain intake and gastrointestinal cancers, certain hormone-related cancers, and pancreatic

Dairy

One cup of milk provides 12 g of carbohydrate in the form of lactose. Cottage cheese, which has about 6 g of carbohydrate per cup

what are components of complex sugar?

Polysaccharides • starch• glycogen • fiber

Glucose for energy

Primary function of carbohydrates is to provide energy for cells. Brain is totally dependent on glucose for energy. Spares protein and prevent ketosis ( buildup of certain acids) simple sugars and complex carbohydrates provide 4 cal/g.

How to increase dietary fiber

Replace refined grains with whole grains. Choose a ready-to-eat cereal with 5 g of fiber or more per serving. Eat dried peas and beans two to three times per week. Eat at least five servings of fruits and vegetables daily. Eat a variety of plant foods daily. Increase fiber intake gradually to avoid GI intolerance. Consume adequate fluid.

"Refined" grains

Rich in starch but lack the fiber, vitamins, trace minerals, fat, and phytochemicals found in whole grains Enrichment Required to be fortified Examples include white flour, white bread, white rice, and refined cornmeal

When the body does not have an adequate intake of glucose, the formation of ketone bodies increases. Increased production of ketones has several side effects. What is one of these side effects? a. Increased appetite b. Potassium depletion c. Nausea and vomiting d. Sodium depletion

Sodium depletion (An increased production of ketone bodies and their accumulation in the bloodstream causes nausea, fatigue, loss of appetite, and ketoacidosis. Dehydration and sodium depletion may follow as the body tries to excrete ketones in the urine. )

The most common sources of added sugars in the American diet

Soft drinks Cakes, cookies, and pies Fruit drinks and punches Dairy desserts such as ice cream Candy

Vegetables

Starch and some sugars provide the majority of calories in vegetables. "Starchy" vegetables provides three times more carbohydrate than the same amount of "watery" vegetables.

Glycemic index

To assess a food's impact on blood glucose response more accurately a numeric measure of the glycemic response of 50 g of a food sample; the higher the number, the higher the glycemic response. Determined by comparing the impact on blood glucose after 50 g of a food sample is eaten compared to the impact of 50 g of pure glucose or white bread May help diabetics and athletes

Nonnutritive sweeteners

Virtually calorie free Sweeter than sugar Do not raise blood glucose levels Risks and benefits of nonnutritive sweeteners Weight management Diabetes mellitus Safety

A diabetic diet is now based more on keeping the total carbohydrate intake consistent with less emphasis on the source of the carbohydrate. What has this change in focus meant for diabetic diets? a. Sugar alternatives are substituted for simple sugars. b. Sweets can be included in the diabetic diet. c. Calorie control is most important for diabetics. d. Diabetics need to learn the glycemic load of foods.

b. Sweets can be included in the diabetic diet. (Rationale: Contrary to what was previously believed, regular sugar does not raise blood glucose levels more than complex carbohydrates do; a food's glycemic load is influenced by several factors, not just sugar content. The focus in management of blood glucose levels has shifted from avoiding simple sugars to maintaining a relatively consistent total carbohydrate intake with less emphasis on the source. For that reason, sweets can be included within the context of a nutritious, calorie-appropriate, carbohydrate-controlled diet. )

Glucose metabolism

balance between catabolism and anabolism

Phytochemicals:

bioactive, nonnutrient plant compounds associated with a reduced risk of chronic diseases.

catabolism

burning glucose for energy

Added Sugars:

caloric sugars and syrups added to foods during processing preparation or consumed separately; do not include sugars naturally present in foods, such as fructose in fruit and lactose in milk.