Dr. Éanna Falvey:

Yes, the companies sell it but the problem is not the protein. That is too simplistic a way of looking at the issue. That is marketing. The companies would love to hear that it is the protein that is causing the players to get bigger. The reason children get bigger is that from the age of 15 on players are involved in structured weight programmes. In fact, there is good evidence to show that if one has a well-balanced diet with proper protein intake, that is every bit as good for getting big as taking a protein supplement.