Macronutrients Carbohydrate Function

Carbohydrates and Nutrition There have been major advances in the understanding of how carbohydrates influence human nutrition and health in recent years. Progress in scientific research has highlighted the diverse functions of carbohydrates in the body and their importance in the promotion of good health.

Energy & Taste   Energy: cell respiration   Transformation of glucose to ATP fuels the body’s functions   The brain, nerve cells, and developing red bloods cells use glucose almost exclusively for energy   Dietary carbohydrates provide the carbohydrates needed for this process   Taste/Flavor / Sweetness (sucrose, fructose)

Intestinal Health & Cellular Recognition   Proper intestinal health (fiber)   Structural components of glycoproteins and glycolipids; these are used for cellular identification – how your body recognizes itself (example: blood type)

“Protein Sparing”   Protein sparing (gluconeogenesis)   The body cannot convert fats into glucose [for cell respiration] to a significant degree (large amounts).   So without glucose, the body may be forced to break down its protein tissues in order to convert to glucose for energy, which can lead to muscle loss.

Avoiding Ketoacidosis   Fat metabolism  prevents incomplete breakdown of fats; prevents ketone production   When the body uses fat for energy, fat fragments combine to form ketone bodies.   Some body cells can use ketone bodies for energy, but if fat is broken down too rapidly, ketone bodies begin to accumulate in the blood.   This can cause a serious condition called ketosis that can lead to coma and death.

Amount of Dietary Carbohydrates You Need…   The body needs at least 50 to 100 grams of carbohydrates a day to spare body proteins and prevent ketosis

Simple Sugars   Some examples of simple sugars are glucose, fructose, sucrose, and lactose   Food sources for simple sugars??

Complex Carbohydrates Some examples of complex carbohydrates are starch, glycogen, and fiber

STARCH Starch is the most consumed polysaccharide in the human diet Found in rice, wheat, corn, and potatoes, peas, bananas, various forms of bread and noodles (including pasta). Cornstarch is used in cooking for thickening foods such as sauces Plants store glucose as amylose and amylopectin (types of starches)

FIBER   Dietary fibers are the indigestible portion of plant foods   Non-starch polysaccharides such as cellulose   Fiber is NOT used for energy

Insoluble Fiber Functions of Insoluble Fiber Move bulk through the intestines Control and balance the pH (acidity) in the intestines Benefits of Insoluble Fiber Promote regular bowel movements and prevent constipation Remove toxic waste through colon Help prevent colon cancer Food Sources of Insoluble Fiber Vegetables such as green beans and dark green leafy vegetables; Fruit skins and root vegetable skins Whole grain products; Seeds & Nuts

Soluble Fiber Functions of Soluble Fiber Prolong stomach emptying time so that sugar is released and absorbed more slowly (makes you feel full longer) Benefits of Soluble Fiber Lower total cholesterol and LDL cholesterol (the ‘bad cholesterol’) therefore reducing the risk of heart disease Lowers blood sugar Food Sources of Soluble Fiber Oat/Oat bran Soybeans and peas Nuts & Barley Some fruits particularly prunes, plums, berries Vegetables such as carrots, green beans, celery

GLYCOGEN Surplus glucose is linked together and stored as glycogen Functions as the body’s main energy reserve If there is no glucose, glycogen is available to be broken down into glucose and used

Glycogen Continued… The conversion of glucose to glycogen and glycogen to glucose are the usual mechanism for maintenance of normal levels of blood sugar