Changing people's diets and their knowledge/access to cook is way more important than fat drugs. North America is fat as hell because no one cooks anymore. It's pretty rare to see the massively obese people who are also home cooking for themselves all the time. There are chubby people who cook for themselves, but that's a separate issue from the social issue of obesity which is almost entirely caused by bad food subsidies, advertisements, fast food restaurants, unhealthy food production/preservation in general, and the current family situation of fewer people living in houses together with more people working concurrently.