I am pretty interested in weight loss (but I am not a professional), I will try to explain.<p>First, the stance of medical profession is to treat diseases. There is not much effort on preventing diseases. They will wait until you get sick and then when you pass a magic threshold will assault you with a battery of treatments. We know that diabetes takes <i>decades</i> to develop, yet our description of a person who is halfway to developing diabetes is still "healthy". You need to wait until your body gets so devastated by your bad diet and habits that it gets completely disregulated and you put on a lot of fat before suddenly being considered a subject for treatment.<p>Second, the dissemination of knowledge in medical profession is glacially slow. Even if the research progresses quite fast, it takes a generation of medical professionals to die out and newly trained people to replace them to actually update the knowledge as it is being practiced. We are still in the "fat is bad" times even though we know and have known for a long time that it is actually carbs, processed food and bad fats that are major contributing factors to the obesity epidemic (that plus sedentary lifestyle, stress and bad sleep).<p>Third, people in the medical profession are heavily penalised for having a different view on things to the point that most are scared to speak up. For the most part, practicing anything that is not in line with mainline view will get you expelled from the profession and barred from practicing medicine ever again.<p>Fourth, the dieting, while sounding nice as a solution, does not tend to work well. Most people are unable to stick to a diet long term. Managing early diabetes with a diet would require sticking to it religiously and permanently. Medical professionals are not stupid and know that that's something that very few people can actually do.