Whey Protein Isolate is the perfect protein. It is rich in essential amino acids, which are the building blocks of healthy bodies. WPI also has the highest biological value of any protein source, which means it is the most efficiently digested and utilized protein available. WPI helps produce energy as well as build and repair body cells, muscles, and bones. It is also a key ingredient in many weight loss and meal replacement products because WPI is virtually fat free, carbohydrate free, cholesterol free, sugar free, and lactose free.