That part is easy. But did being fat lead to health problems (that then also kill you), or did health problems lead to being fat (which then also kills you)?
And that is before we get into the entire bit where the data shows that most of the difference comes from lives lost at mid age (betwqeen ages 5 and 40), which is younger than the range where "being fat" typically catches up to you.
I would suggest that poor diet and a sedentary lifestyle lead to both people being fat and to health issues. FWIW, it's been a common pattern for friends of mine who visit the US for even short periods of say 2 weeks to put on small but noticable amounts of weight.
> visit the US for even short periods of say 2 weeks to put on small but noticable amounts of weight
As a European who lives in USA and visits back frequently: can confirm.
In Europe I fight to keep weight on, in USA I fight to keep weight off. Despite counting calories, working out like a maniac[1], and predominantly eating clean. Pre-packaged highly processed foods are like a 1x/month thing, takeout happens max 2x/week, and eating out once or twice per week.
And yet, USA wants to make me fat while EU feels like I can barely eat enough to maintain weight.
[1] my usual week is 7 workouts split between cardio and hiit. Right now I'm in marathon training so going to hit 107km of running this week.
