Also, it's become pretty clear that anorexia embodies a particular kind of dysfunctional dynamic between body perception and diet (one that is gaining recognition in other forms of dietary restriction, as sometimes seen in e.g. athletes and people obsessed with various categorizations of "natural" or "pure" foods). The vast majority of obese people aren't building an elaborate system of memes and rituals to force themselves to overeat because they look in the mirror and see themselves as thinner than they really are.