I'm assuming he lives with them, yeah (isn't it canon? at least it's heavily implied, otherwise idk where I'd get it from :D), but if they don't even know enough about his work, they may not be all that interested in what he's eating? Plus he just graduated college, where he probably learned to eat in a way that would make him fit right in with the SID. :D But I'm equally in favor of both headcanons - this one, and the opposite one where he eats great nutricious meals at home and is horrified to see how much it's not the case at work. :D