Dietary protein delivers nutrients known as amino acids (AAs) that are essential building blocks for all the body’s structures and functions. Your whole body is built from the AAs in your diet. Twenty total AAs occur naturally in the food you eat. Of these, nine must come from your diet—in the correct amounts and proportions—because your body can’t make them. These nine are called essential AAs. Your body uses AAs to form and maintain your muscle, bones, ligaments, and tendons, as well as organs. Insufficient dietary intake of AAs leads your body to prioritize sending AAs to build organ systems and other priority functions before building muscle.
