Proteins are complicated molecules formed from building blocks called amino (uh-MEE-no) acids. There are approximately 22 different kinds of amino acids that can combine to form many types of proteins. Your body can make 13 of the 22 amino acids. The rest are essential nutrients that the body must receive from the diet. You need protein to make new tissue, to grow, and to maintain and repair cells. If you don't get enough protein, it results in stunted growth and impairment of your body's ability to heal itself. However, most people in the U-S and other western countries consume far beyond the daily recommendation of protein, which can hurtyour health. Eating more protein than your body needs, requires extra work to digest and metabolize, which can tax the liver and kidneys. Excess protein also can leach bones of important minerals, which can cause diseases such as osteoporosis.