To take the time to study the root causes of obesity more closely, and treat the genuine causes, instead of slapping medicine on top of it, for an undetermined period of time to millions of people. It's insane.
Obesity at that scale is a recent issue[0], I'm sure we're clever enough to figure it out.
Think about it: as far as we know, the human body has evolved slowly over many thousands of years; how can drafty-patching it at scale over a few decades works? When something as inconspicuous as switching from stale bread to softer bread has had a drastic impact on dental issues[1]?
It's like a junior dev undertaking a major rewrite on his first day of work.
I'm reluctant to argue much further, I doubt it'll change much for either of us.
[0]: https://www.ncbi.nlm.nih.gov/books/NBK44656/
[1]: https://www.youtube.com/watch?v=3wWg9Jx-Byw (French, English papers in the description if you want to dig)