answer:I haven’t read up on the protein drinks, but I do know people who use them and seem to get good results for muscle building. With my basic knowledge of nutrition from college I would say both whey and casein are complete proteins, and so are meats like chicken, fish, beef, and other dairy products like milk and cheese. If I had to guess, people who use the protein drinks, take in much more protein than the average diet. For body building more protein will help build the muscle. Casein also digests more slowly, so I guess whey might get to the muscle faster if you just worked out. Having said all of that, I did not provide you with studies, but I have two warnings. Many of these products are very high in cholesterol, check the labels. If you don’t have a cholesterol problem, then it might not be a concern, but I know a lot of body builders that have their cholesterol very bad, very high numbers and horrible ratios. I would have yours checked to get an idea if it is something you should watch. I have seen whey powders vary from 15mg cholesterol per serving to 75mg, abig difference. The other warning is if you begin to have a lot of acne, it is probably from something associated with the body building.