I always start with characters rather than with a plot, which many critics would say is very obvious from the lack of plot in my films - although I think they do have plots - but the plot is not of primary importance to me, the characters are.
I've never really talked about this, but I would go days without eating. Or maybe I'd have some fruit and then go to the gym for three hours. I knew I had a problem... It was a gradual process but I changed myself.