@Ayumeya So what? If someone offers me a food I dislike, I say "No, thanks". I don't
steal it from them. Oh sorry, "confiscate". Heh, everyone's up in arms about the kid stealing the bun (and rightly so), but the teacher stole a whole box of food from her under cover of authority, and not even because he wanted it, but just to be a prick. That seems the bigger crime to me.
And just what category of food you or he deems it to be strikes me as irrelevant. Sure, if all she was eating was a bag of marshmallows he might want to get her to eat something healthy--but she'd already eaten a balanced lunch, and indeed made sure the other kids did. If there's some rule against a snack of any sort with lunch, that would be a stupid rule--but he cited no such rule, he just arbitrarily took her stuff. As far as can be told from the manga, he just took it because the stuff makes him antsy because of memories of his grandmother being a bitch while she fed it to him. But he's an adult with responsibilities; pulling arbitrary bullshit to make his students feel bad because he has issues is failing those responsibilities.