I think this mostly has to do with the extensive use of vegetables cooked in various tasty ways. Western dishes (specifically West European) seem to have very few good techniques to cook vegetables, leading white children to hate veggies. I think this is exacerbated in Britain and their Anglo-Saxon colonies (cue the meme about British food having no seasoning).
Also, proper Asian dishes tend not to actually use much oil. Stir frying only lightly coats the outside of food with oil, very different from western deep frying.
Sorry, I've only been there once, but from what I have been told by canadians / americans, fast food is consumed quite frequently there. They even eat breakfast at fastfood restaurants.
I sound like a boomer lol, I know that there are many different dishes, but the general eating habits seem to be way unhealthier than in other parts of the world. I have never seen so many overweight people anywhere else, though I don't blame them individually, the problem is systematic.