I lived in Normandy for a bit. You're not wrong on portion control. I was almost constantly hungry for the first month or so it took me to adapt. Same on walking. It's a small enough place, and public transport is good enough that there's no real need for a car. Add in painfully high gasoline prices, and the fact that people live in places where they can walk to things like the market and butcher. and you get more walking almost automatically. I went through a lot of boot heels just doing the French 'normal' amount of walking.

Also on diet, they ignored the hysteria on saturated fats, didn't replace them with "low fat" (really high sugar) foods. In Normandy, cows eat grass year-round. Only just now are some Americans waking up to the benefits of grass-fed butter.

You're also right on snacking. Just wasn't done there. Now, we know that we need 12 hours of not eating for gut health, and more like 16 for a metabolic switch between glucose and ketones. That said, I didn't know anyone there who fasted - but I did have friends I was eating with stop eating with the comment "too much food". Kind of an eye opener to an American kid who learned to 'clean his plate'. Also, the typical morning breakfast of just a latte (espresso w grass-fed cream), likely didn't break the overnight fast as far as metabolism switching is concerned.

On the downside, they pretty much all smoked, and likely still do. Conversationally, I heard more about liver health than any other health issue.

Speaking of the "Amer-we-can" gap shrinking, there were no fast food places then. I made a point of visiting the single MacDonald's on a holiday to Paris, went in hoping to get a burger (hey, the things you crave when they disappear) - and there weren't any on the menu. Apparently the Parisians were uninterested in burgers - and given a comparison to, say, a sausage sandwich on baguette, I can't really blame them.