I'd like to know that as well. I suppose one part of it is addiction, for those that are addicted to eating. For some it's possibly habits. A habit is hard to break (albeit not impossible).  For some it might be some type of acceptance? "Yeh I look like this, might as well accept it tehee". I mean, I don't like my face. Plastic surgery aside, my face is gonna look the way it looks. Nothing I can do about it, just gotta accept it. Maybe fats look at their.. fat and think that it's easier to accept it than to fix it. I don't know, I'm just throwing out thoughts here.