I still remember driving through some small town in Arizona 10 years ago, and I couldn't find a single non-obese person there. Not just overweight, full on obese. Parents, kids, everyone. It was the one of the most bizarre experiences I've had, as a visitor. Cities are not that bad though, but I'm sure many rural parts are close to 100%.
I've only ever visited San Francisco in the US, and the first time I was there I was slightly surprised that in terms of obesity it seemed pretty similar to Dublin (which wouldn't be the thinnest city around, but is middle of the road European). Then I flew back via O'Hare, and really saw the difference when waiting for the transfer; quite dramatic levels of obesity. I wonder how much of it is just down to urban Amer…
The added sugar in the US is a shame. Just this year, the nutritional labels are mandated to show added sugars in products now. I hope that helps.