They don't understand nutrition is like sports or math, the more you do it, the better you get at it. Making choices gets easier every time you keep on pushing yourself. If I want McDonald's really bad (it's never happened, just an example), what carbs should I give up in order to fit it in? Do I really want the fries? Do I really want the soda? This kind of thinking is what makes people not balloon up and, yet, it's a concept completely out of obeast's grasp.