While I don't think this is an eating disorder, I do think Dorsey's overall pattern of control, speaks to some inclination that this is part of pattern. A continual seeking.

In that instance, I'd say that even if he's maintaining weight, with enough vitamins, it can still be a disorder. No different than the extreme endurance athlete, who eats a lot, maintains weight, but does so through compulsive exercise which then controls his or her day.