When I was there 2 years ago we got the impression that Americans were bigger overall whilst UK were more likely to be either slim or very over weight....?
But perhaps we like in an area of depravation and have jobs which means we meet people who are obesity.
it depends on where you are - things are different in various regions. If you go to suburbs, you're likely to find less obesity than you will in rural areas, and more people doing serious regular exercise. And then by region beyond that (as in, philadelphia is likely to have a higher % of people overweight than san francisco, and probably higher than chicago).
(I just looked at the CDC map - I would've guessed above that income is the differentiator - higher income, lower obesity. It is. But the CDC also maps it to level of education - which obviously is tied to income. Life expectancy is also highly tied to income to a point, too -but also by profession. I tease my parents because they groan about all of their years being teachers, but they saved their money and retired at 54. Life expectancy for teachers is higher than it is for white collar workers in general, and white collar workers much longer than blue collar on average.
And having seen a lot of folks talk about how dangerous their jobs are and how their life expectancy is so short because of it, some occupational information has become available in the last couple of decades (?) - and jobs like police and fire overall have no shorter life expectancy than the general population - whatever hazards there may be are balanced out by generous retirement benefits avoiding poverty in retirement.
I had a broadcast engineer tell me once that the job was so hazardous that everyone makes it to retirement and dies within two years. He saw it in a newsletter for the group, therefore it was fact.
I asked him "so, this job is so hazardous that it kills everyone within two years after they stop it, but it doesn't cause anyone to die while they're doing it?" His answer was "yes". I don't actually know what a broadcast engineer is, but I'm guessing it's not the same thing as like an electrical or mechanical engineer - though I know a few engineers in my neighborhood who won't be swayed from their irrational fears by actual odds and outcome data.