Whey protein isolate is one of the cleanest and purest sources of protein available today. Cheaper protein sources, like milk protein or casein, have higher levels of lactose and fat. Whey protein isolate (WPI) is naturally low in fat and very low in lactose. In addition, whey protein concentrates and protein blends typically only contain about 75-85% protein as they also contain more lactose, carbs and fat.
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