Learning the importance of protein is key to reaching your fitness goals. Protein is essential for building and repairing muscles, red blood cells, hair and other tissues, and is necessary for synthesizing hormones.
Protein is digested into twenty-two amino acides, thirteen of which the body manufactures. Since the human body cannot manufacture the other nine amino acids, they are known as essential. A "complete" protein supplies these essential amino acids. An "incomplete" protein lacks one or more of the essential amino acids. These incomplete proteins are generally from plants. By combining grains with legumes the nine essential amino acids can still be obtained without necessarily eating animal products. The RDA for protein for adults if 0.8-1.0 grams of protein for each kilogram (2.2 pounds) of body weight.