Isn't that the elephant in the room? Billy has an eating disorder? I would think we;ve all noticed his weight fluctuation over the years. Sorry, I'm new to this board.
There;s a youtube vid where he talks about he was physically abused as a kid/teenager and he used to cut himself, do sleep deprivation, how he was really OCD about his baseball cards etc. He's been pretty open about it. These are all coping mechanisms for abuse AFAIK.