I don't necessarily think you can lump all Asian food in together. Japanese food uses little oil, for instance. Very little seasoning too. Actually I've been told by Chinese people here than American Chinese food is oily and disgusting, so there you go 😃 I am told that authentic Japanese places in the US differ quite a bit from Chinese run or US run Japanese places, to give another example. I think all ethnic food is a little altered to suit the country they are in. Indian places here are super common, for example, run by real Indians, but I am somewhat doubtful if the "Japanese Indian food" is the same as the actual food I would get in India.

Yeah, Japanese students going to the States for a year or two always complain to me about how massive US servings are. 2-3 times bigger than in Japan. I often suggest what you do, but sharing a single dish or taking leftovers hope is considered rude here, so they are often hesitant to do it. I keep suggesting though. When in Rome, right?