CARBOHYDRATES

 Chapter 2: Carbohydrates Joe Pistack MS/Ed

CARBOHYDRATES

 One of three energy nutrients (the others are fats and protein)  Manufactured by green plants in a process known as photosynthesis  Two major groups: sugars and starches  All carbohydrates (CHO) are not equal in terms of health benefits from eating

CARBOHYDRATE COMPOSITION

 Molecule – smallest quantity a substance can be divided into without loss of its characteristics  Element – can not be separated into simpler parts by ordinary means – composed of atoms  Atom – smallest particle of an element that maintains their chemical properties

CARBOHYDRATE COMPOSITION

 Carbs are composed of the elements carbon, hydrogen, and oxygen  The ratio of hydrogen to oxygen is 2:1 just like water H 2 O

CARBOHYDRATE COMPOSITION

 Includes monosaccharides and disaccharides  Mono = one and di = two  C 6 H 12 O 6 chemical formula  Note: the same ratio of hydrogen to oxygen as water (H 2 O)  Mono is one unit of C 6 H 12 O 6 and di is two units of C 6 H 12 O 6 minus one unit of H 2 O

MONOSACCHRIDES

 Building blocks of all other CHO  The three monosaccharide's are glucose, fructose, and galactose  All mono and di saccharides end with “ose”

MONOSACCHRIDES

 Glucose is commonly called blood sugar — the body converts all forms of sugar consumed to glucose  Another name for glucose is dextrose (abbreviated D)  IV fluid is frequently D 5 W which is 5% dextrose in water

MONOSACCHRIDES

 Fructose is found in fruits and honey  The sweetest monosaccharide  The body readily changes fructose to glucose

MONOSACCHRIDES

 Galactose – comes mostly from the breakdown of the milk sugar lactose  Yogurt and un-aged cheese contain free galactose  It is the least sweet of the monosaccharide's and it too gets converted into glucose

DISACCHARIDES

 Disaccharides are two monosaccharides linked together  The three important disaccharides are  Sucrose  Lactose  Maltose

DISACCHARIDES

 Sucrose – the most common disaccharide. Also known as ordinary white table sugar  Made commercially from sugar beets and sugar cane  Brown, granulated, and powdered are all forms of sucrose  Also found in molasses, maple syrup, fruits, and vegetables

DISACCHARIDES

 Lactose – occurs naturally only in milk  Least sweet of the disaccharides  Made from the monosaccharides glucose and galactose

DISACCHARIDES

 Maltose – double sugar that occurs primarily during the digestion of starch as the body breaks it down into simpler units  Small amounts are found in malt, malt products, beer, some infant formula, and sprouting seeds  Maltose consists of two units of glucose

SUGAR ALCOHOLS

 AKA - Sugar replacers (Suplena ® ), Polyols, Nutritive sweeteners, Bulk sweeteners  Lactitol, maltitol, isomalt, sorbitol, xylitol, and mannitol are sugar alcohols approved and used in the US  Used as a 1:1 substitute for sugar

NON-NUTRITIVE SWEETENERS

 Intense Sweeteners  Sugar substitutes such as artificial sweeteners  Saccharine  Do not add bulk or volume, only sweetness  150 to 500 times as sweet as sugar

COMPLEX CARBOHYDRATES

 Also called polysaccharides  Three nutritionally important complex carbs  Starch  Glycogen  Dietary fiber

STARCH

 Starch —major source of carbohydrates in diet  Primarily found in grains, starchy vegetables, legumes, and food made from grains like cereal, bread, and pasta

GLYCOGEN

 Glycogen - animals, as well as humans, store glucose in the in liver and skeletal muscle tissue in the form of glycogen  During physical activity muscle glycogen is converted to glucose  During sleep liver glycogen is converted to glucose as needed

DIETARY FIBER

 Dietary fiber refers to the food, mostly from plants that is non digestible  It adds bulk to our foods  Sometimes called roughage, it sweeps out our intestinal tract

DIETARY FIBER

 Food and Nutrition Board recommends  Men 50 years or younger: 38 grams per day  Women 50 years or younger: 25 grams per day  Men over 50: 30 grams per day  Women over 50: 21 grams per day  Average fiber intake in the United States only 15 grams per day  Eating too much fiber not recommended

SOLUBLE FIBER

 Soluble fibers – dissolve in water and thicken to form gels  Include beans, oatmeal, barley, broccoli, citrus fruit, and oat bran (particularly good source)  Health benefit –  Lower cholesterol  Regulate blood sugar  may promote satiety

INSOLUBLE FIBER

 Insoluble fiber does not dissolve in water  Wheat bran, corn bran, vegetables, nuts, fruit skins, and some dry beans contain insoluble fiber  Health benefits –  promotes regularity  may reduce risk of some forms of cancer  may reduce risk of diverticular disease Everyone needs both kinds of fiber in the diet

CARBOHYDRATE FUNCTIONS

 Provides fuel  Spares body protein  Helps prevent ketosis  Enhances learning and memory

CARBOHYDRATE FUNCTIONS

 Provides fuel – carbohydrates, fats, and proteins provide energy for the body's needs  Carbohydrates are the primary source of fuel for all cells  The brain is a carbohydrate dependent organ needing a continuous and uninterrupted supply of energy

CARBOHYDRATE FUNCTIONS

 Spares body protein – if carbohydrates and available glycogen stores are depleted, the body can convert protein into glucose.

 In the absence of carbohydrates the body will break down internal protein before fat

CARBOHYDRATE FUNCTIONS

 Helps prevent ketosis  The body can not handle the excessive breakdown of stored fat because the body lacks the necessary resources. As a result partially broken down fats accumulate in the blood and form ketones, putting the body into ketosis  Very low carb diets are not recommended

KETOSIS

 Ketosis causes fatigue, nausea, and loss of appetite  Detection of ketones is easily done with a urine test looking for the presence of acetone or diacetic acid  Coma or death can occur in severe cases

HEALTH AND CARBOHYDRATES

 The kinds of carbs are important  High intake of fruits and vegetables lower risk of chronic disease  Legumes are low fat and high in protein  Whole grains lower risk of heart disease and some cancers

CONSUMPTION PATTERNS

 Most of the world’s population subsists on CHO  Much research has shown that Americans and Canadians are eating too much of everything (except fiber), including CHO  Of particular concern is the excessive intake of sugar from sweetened carbonated beverages  Six servings of whole grains are recommended to increase fiber intake  Whole fruit and vegetable intakes are also lower than recommended levels

CARBOHYDRATE CONSUMPTION AND DENTAL HEALTH  Genetic susceptibility  Other factors related to cavity formation  Length of time food is in the mouth  Food texture  Frequency of food intake  Acidity of food  Foods that help: aged cheeses and fibrous foods that stimulate saliva production

CARBOHYDRATE FOOD SOURCES

 As a food source carbohydrates are broken into two general groups  Sugar  Starches

CARBOHYDRATE FOOD SOURCES

 Sugars – table sugar contains about 4 grams of carbohydrates per teaspoon  When determining a persons sugar intake simple sugars like honey, jam, and jelly need to be considered as well as the sugars in carbonated beverages, ice cream, cakes pies …

STARCHES

 Emphasis on whole grain  Make half of your grains whole - examples are  Oatmeal  Whole wheat  Graham crackers  Pumpernickel and Rye bread – sometimes  Barley

CARBOHYDRATE FOOD SOURCES

 Starches – complex carbohydrates and are an important source of fiber and other nutrients  Whole grains are more nutritious than refined grains as some nutrients are lost in the milling process  Oats are not normally milled

GRAINS

 Whole grain is constructed of three general parts  Bran – outside shell (this gets crushed in the milling process)  Germ - part of the contents  Endosperm – majority of the contents  Most nutrition is in the bran and germ

EXCHANGES LISTS

• • •  Lists designed to make equivalent food substitutions based on Portion sizes – How much oatmeal would provide 15 grams of CHO?

Food composition – How much fat is in orange juice? How foods compare to each other within a given list – 1¼ cups strawberries = ⅓ cup grape juice

EXCHANGE LISTS

 Exchange lists provide swap information for the following groups:  Starch/Bread Exchange  Vegetable Exchange  Fruit Exchange  Milk Exchange  Estimating the Fiber Content of Foods

DIETARY RECOMMENDATIONS

 Focus on fruits (whole fruits are better than juices) —Eat 2 cups of fresh fruit per day  Vary your vegetables —Eat 2½ cups per day  Make half of your grains whole: whole-grain cereals, whole-grain breads, corn, whole grain rice, and whole-grain pasta  Milk contains CHO —Eat or drink three servings a day from this group