I'd add to this: With abundant choices of carbs available, you can pretty much control weight gain based on which ones you consume. Sugar is first to go, followed by wheat, then corn, and at that point you're pretty much down to a collection of things that are hard to gain weight from (because they're a combo of fibrous and less exciting.) On the fruit side, bananas and grapes are probably worst, then apples and similar behind that, with berries being a somewhat safe bet on the other end.