Protein powders are used in drink mixes to provide supplementary protein to the diet. Many preparations of protein powders have been developed and often include whole milk proteins, whey protein, casein, soy protein, egg albumin, and combinations of these. Although drinks produced from protein powders can offer a convenient source of protein and essential amino acids, research has not demonstrated their efficacy over whole foods in the development of lean body mass in exercisers. The entry for proteins provides more detail regarding the protein needs of athletes.