I've no way to tell, but something tells me not all grade schools devote the same amount of time to teaching students about nutrition.
I'm not trying to be combative here, but making those arguments just buys into the idea that, if someone gets fat, it's all their fault-- and they have't paid attention to what they've been told, and what they've been told is the right way to eat. It's essentially saying that doing what you're told by certain people is better than thinking about it-- in other words, be gullible.