This is correct from my perspective as well (I live in Japan). Not just portion sizes, but total calories in a meal are dramatically smaller. I went back to t

This is correct from my perspective as well (I live in Japan). Not just portion sizes, but total calories in a meal are dramatically smaller. I went back to the UK a week ago for a visit and I was stunned to see menus with calories listed that had individual meals (without drinks or desert!) listed as considerably over 1000 kcal. Japanese people often have a good breakfast, but then eat maybe 5-700 kcal for lunch (in the form of a bentou) and maybe the same for dinner. Sometimes you get a set bentou at work and it often works out to about 1000 kcal -- but nobody I know who eats those ever eats dinner. They'll have a drink or two after work with whatever otoshi (side dish imposed on you as a cover charge in the drinking establishment) and maybe some snacks.