Like fats and carbohydrates, protein is an essential dietary component, providing calories that can be used by the body as a source of energy. It is also essential for the growth and maintenance of body tissues; for the productionof hormones, enzymes, and antibodies; and for the regulation of bodily fluids. Protein should account for about 12 to 15 percent of calories; in a 2,000-calorie diet, that translates to approximately 240-300 calories (60 to 74 grams). Children, pregnant women, and nursing mothers will require more protein to support growth. Illness, infections, attacks on the immune system, and malnutritiion can also affect how much protein the body needs and how well it can use the protein it receives.
The average American eats 100 to 120 grams of protein daily, nearly twice the recommended level. Too much protein can be as detrimental to the body as toolittle because excess protein is linked to osteoporosis, dehydration, and gout. An excess of protein can also damage the liver and kidneys.
The Professional Chef, 7th Edition by The Culinary Institute of America