Comment by Jensson

What about them? Are they designed to make you overeat? Or do they fill you up? I don't know which is why I ask. It is possible that they regulated things differently or their food companies had different values so they engineered snacks and fast food to not make you overeat.

As I said, engineering food isn't bad in itself, it depends on what goals you have when you engineer it. Just because Japanese people eat a lot of engineered food doesn't mean it is bad for them if that food wasn't engineered to make them fat.

Many say they slim down as they visit Japan, so I wouldn't rule it out.

What I'd want to see is if two countries that has the same snacks available had vastly different outcomes. But as far as I know most countries has domestic snacks so it varies wildly around the world. For example, why is Czechia much fatter than Slovakia? They were the same country 30 years ago.