Whey protein isolate is a complete protein, which means it has all of the amino acids that are needed in a daily diet. It contains high levels of branched chain amino acids. Branched chain amino acids are unlike other amino acids in the promotion of muscle growth because they can be metabolized directly into muscle tissue.
Whey protein isolate contains a high level of leucine, which promotes the synthesis of muscle protein and muscle growth. It also promotes the loss of fat tissue because of the energy the body needs to process leucine. When compared with soy protein isolate, whey protein isolate has 50 percent more leucine.
Whey protein isolate has a high level of cysteine. According to the Whey Protein Institute, whey protein boosts the immune system. It does this by elevating the body’s level of glutathione