NUTRIENT FUNCTION MAJOR SOURCES
Proteins (4 calories/gram) Form important parts of muscles, bone, blood, enzymes, some hormones, and cell membranes; repair tissue; regulate water and acid-base balance; help in growth; supply energy Meat, fish, poultry, eggs, milk legumes, nuts
Carbohydrates (4 calories/gram) Supply energy to cells in brain, nervous system, and blood; supply energy to muscles during exercise Grains (breads and cereals), fruits, vegetables, milk
Fats (9 calories/gram) Supply energy; insulate, support, and cushion organs; provide medium for absorption of fat-soluble vitamins Animal foods, grains, nuts, seeds, fish, vegetables
Vitamins Promote (initiate or speed up) specific chemical reactions within cells Abundant in fruits, vegetables, and grains; also found in meat and dairy products
NUTRIENT FUNCTION MAJOR SOURCES Photo Gallery
Minerals Help regulate body functions; aid in growth and maintenance of body tissues; act as catalysts for release of energy Found in most food groups
Water Makes up 50-60% of body weight; provides medium for chemical reactions; transports chemicals; regulates temperature; removes waste products Fruits, vegetables, liquids
Food is partially broken down by being chewed and mixed with saliva in the mouth. After traveling to the stomach via the esophagus, food is broken down further by stomach acids and other secretions. As food moves through the digestive tract, it is mixed by muscular contractions and broken down by chemicals. Most absorption of nutrients occurs in the small intestine, aided by secretions from the pancreas, gallbladder, and intestinal lining. The large intestine reabsorbs excess water; the remaining solid wastes are collected in the rectum and excreted through the anus.
