I'm actually not sure diet and exercise does help much once you're already fat. I think it can keep you from getting fat, and I think the story has to be make sure you don't get fat. But once you have the fat, the body has a strong, strong predisposition to making sure you don't lose it. When it comes to weight, we are primed to not losing it like those one-way traffic spikes when driving out of a pay parking lot.