fatchance:
Remember, that your weight is different from your fat. When you gain, once you gain a certain amount, your fat cells get "full" and your body makes more fat cells.
When you lose, the fat cells get smaller, but you do not lose any of them. In a sense you remain "fatter" even as you lose weight. You will always have to limit calories and/or burn extra calories in some combination to avoid gaining the weight back because your body wants to restore all those shrunken fat cells to normal size.
So in a certain sense, getting fatter is a one way street and your body considers any lose of weight starvation because those fat cells are shrunken.
The exception is within the "normal size" range of the fat cells. Your weight can vary quite a bit, especially if you are fat, maybe +/-10% or something, while keeping your fat cells in the normal range.
But there aren't ways to destroy fat cells? I am sure that such a thing does exist