mysterio: Yes. This is exactly correct.
Yes, and the reason is that going off a diet puts your eating habits back where they made you gain so much weight in the first place. The most important thing is to find a diet that you can live with forever and stick to it always. Low-fat, high-carb diets make many people hungrier than low-carb, but low-carb takes some getting used to. It's worth the effort though.