Where's your research to prove your assertion? The consensus in the field is that health education classes about diet and exercise have positive benefits, which

Where's your research to prove your assertion? The consensus in the field is that health education classes about diet and exercise have positive benefits, which is backed up in the literature. So, this study really compared against best practice. I don't see the problem. Comparing a new treatment against best practice is ethical when you are dealing with people's lives.