Ditto for carbs (not just white rice but all sorts of wheat noddles and dumplings), and the absolute junk that konbini food and drinks are, which everybody eats all the time.
Discussion
That hasn’t been my experience at least where I live - konbini food not purchased frequently except mostly by kids and old dudes.
Then how do you get three konbinis every half kilometer? Doesn't matter.
Similarly hyperprocessed stuff is used as ingredient by all restaurants big and small cheap and expensive, especially condiments containing soy, "vegetable" oils, MSG, and corn syrup. And supermarkets sell it too, and regardless, it is still very bad junk food.
Japanese people have: 1. better (more favorable) genetics, 2. better lifestyle habits (they move and walk more than Americans), 3. better diet habits despite all (more whole foods including fish), 4. better cultural habits and relationship to food (Americans simply don't care about food that much).
Probably moderate consumption. Variety + all the things you mentioned