Get the stomach flu.
It's like having bulimia for a day or two, without having to gag yourself. Just imagine, 24 calorie free hours!! But you still get to eat ice cream, because it really helps when all that calorie free food is coming back up.
Unfortunately, as it totally blows to have to throw up all the time, I wouldn't recommend doing this more than once or twice a year. But you know, if you're desperate...
Uh, okay, misery really does love company. Just throw up a few times and make me feel better, k?