Protein is widely recognized as a necessary component of the diet, and this is particularly true for body builders and serious athletes. It is also of particular concern to vegetarians who may not get enough protein in their daily diet. Protein is involved in growth of hair, nails, skin and bones. Supplemental protein is necessary for body builders, and also has the added benefits of reducing hunger, which may lead to lower weight, and improvement in diabetes and heart disease symptoms. Casein protein is the main protein found in milk and dairy products. One of the biggest attractions to casein protein is its ability to clot in the stomach, and thus become a more efficient and longer lasting provider of nutrients and amino acids, as well as improving nitrogen utilization in the body.