Where are you getting your numbers? Canada is at ~29% and the US is at ~36%.

Sources: https://en.wikipedia.org/wiki/List_of_countries_by_obesity_r...

https://ourworldindata.org/obesity

https://worldpopulationreview.com/country-rankings/obesity-r...

That's interesting, the CDC lists 42.4% for the US. https://www.cdc.gov/obesity/data/adult.html

Anecdotally, coming to the US from Europe/Japan. The food there is ridiculously fat/large. At least as long as you want to spend less than $30/meal.

Or it's not the food and people have just adopted a lifestyle where all energy expenditure is minimized.

That is self evident in social behavior. Your theory is just an easily trotted out bogeyman.

Anecdotally, it's at least partially the food. I was a little overweight when I moved to the US, and now I'm full blown fat. My lifestyle (aside for food), didn't change.

The main difference is availability and price, especially the latter. A decent lunch near my office in my home country was 20-30 bucks (converted in USD), and I made X/year. Now I make 3-4+ times X, and you can get more food than I can eat at shit like Panda Express for 6-8 bucks. So vs my income, it's almost 10 times cheaper.

If it wasn't for health concerns, it no longer made sense for me to cook. So I just had delivery/takeout almost every day after I moved (switching country is stressful, so I was happy to get all the time back I could get). Then the health issues cropped up. Now I'm trying to dial it back, but its tough.

I know a _lot_ of people who had similar things happened to them after they moved here, and anecdotally again, one of them moved back and started losing weight super fast, without really trying.