Muscle protein synthesis can be stimulated by ingestion of protein sources, such as whey, casein or soy. Protein supplementation can be useful to restore protein turnover after exercise but also to preserve skeletal muscle mass and function in aging adults. Ingestion of large doses of essential amino acids (EAA) or certain protein supplements may be an effective strategy to induce muscle protein synthesis. However, in many cases, it may not be practical or feasible to consume a large volume of amino acids or protein required for an effective response by muscle. Several evidences show how reduced strength and muscle mass, even in early life, are predictors of early mortality which explicit the importance of developing more effective methods to improve muscle quality. Therefore, identifying the better sources of protein that have higher anabolic potency is of high significance.