As you said elsewhere in the thread its calories-in, calories-out. This simple fact is a very big win for science, but it is very unpopular - no one likes to a

As you said elsewhere in the thread its calories-in, calories-out. This simple fact is a very big win for science, but it is very unpopular - no one likes to actually calculate calories, so a lot of people prescribe to dubious unbalanced diets that sound convincing by catering to their food preferences and aesthetics. No regulation short of destroying consumer choice and imposing an approved-foods-list will defeat obesity. Trying to just limit sugar is pointless because industry and consumers will substitute the current form of sugar for something else, raising the cost of food in the meantime, which will hurt the poor. (Just like an import quota on sugar in the US has not reduced consumption of sweets, because sugar got substituted for HFCS). I think the best way to solve obesity is to find some chemicals that satisfy appetite easily and cheaply or sweeteners that are as good or better tasting than sugars, but are not caloric. (Aspartame is very sweet, but tastes significantly worse than sugar).