If you're looking at large countries (>5M) with genetically diverse populations, it's #1. That the top 10 are all smaller countries primarily populated with tho

If you're looking at large countries (>5M) with genetically diverse populations, it's #1. That the top 10 are all smaller countries primarily populated with those with pacific islander/Polynesian backgrounds is remarkable though. Hard to argue there's not something genetic going on there, though apparently there is a cultural preference for larger body size (equating it with material wealth) in at least some such countries. It's presumably also the reason NZ has measurably higher obesity rates than we do in AUS. Perhaps surprisingly the US is only #20 on the list of countries sorted by average BMI, and not that much higher than NZ (or even AUS). I haven't been to the US in well over 10 years now but perhaps we're just playing catch-up here, as at the time I remember being shocked just how many people with truly massive bodies seemed to be commonplace in a way I'd never observed back home. Having said all that, I happen to know there's a school of thought that many (if not most) of the health issues supposedly "caused" by being overweight are largely an artifact of health professionals being so focused on their patients' weight that they fail to diagnose other health issues early on, or that patients no longer feel comfortable speaking to their doctors etc. The fact that the stats on diabetes/stroke/heart failure etc. correlate so strongly with obesity across such a large range of countries, even those where apparently "fat shaming" isn't a thing, leads me to be somewhat skeptical of that POV.