That's not a lack of self-discipline, that's essentially his job. The food isn't really chewed, it goes straight to your stomach where you'll try to digest it, fail, and push it either to the top or the bottom hole. Very little of the calories actually get absorbed and turned into energy. He even described how his weight fluctuates around the competition time (look at the description). And if he just fought his binges (if they were constant due to lack of self-discipline) with exercise, are you aware of how much the guy would have to work? Michael Phelps during training season eats 10 000 kcal a day and trains like a maniac. Matt Stonie eats 20 000+ kcal in one sitting and trains less. Not to mention, Stonie has less muscle mass and height, meaning he should burn way less than Phelps. If anything, I'd say the guy has more discipline than a regular person because of the diet adjustments he has to make before and after competitions.