I think pizza, at least in the United States and during the years around my own childhood, occupied a cultural position that's not fully describable in terms of its nutritional content. Stimulus concerns are sufficient to explain favoring it over something like (plain) oatmeal, but not over something like spaghetti and meatballs or chicken-fried steak.

Ok, I guess I read your first post too quickly. You don't seem to dispute my basic claim that pizza tastes really good. You also don't seem to dispute my claim that children's preference for pizza is evidence of this. Because whatever food children beg for -- whether it's pizza, hot dogs, or curry -- is probably going to be something that tastes good.

I do agree that children ask for pizza -- as opposed to other tasty foods -- for cultural reasons. But I don't think that contradicts any argument I have made.