When did you do that? In last twenty years France has become one of the fattest countries in Europe. I was there in 2008 and 2019. Huge difference.
The upper middle class in USA is fatter than it used to be. Very few people actually lean as opposed to having much less fat. The class disparity is real but not the only explanation.
2014, I still go back annually. You have a large portion of the lower middle class that’s more overweight now but it’s not like in the US where you can be somewhere where it’s impossible to find healthy food for 100 miles, and where you can go inside a Walmart and almost everyone is overweight. There’s obviously some bias given I live in the Bay Area, I’m sure there are areas where upper middle class folks are more overweight.
The upper middle class in USA is fatter than it used to be. Very few people actually lean as opposed to having much less fat. The class disparity is real but not the only explanation.