Works for food too. Even if you completely avoid any obviously unhealthful food (cake, ice cream, candy), it's quite easy to get overweight eating large portions of normal food.
Any time my brother wants to lose weight, he goes to an all-bacon explosion diet[1] and the weight just melts off. Several people at my work went on the so-called paleo diet together and immediately started losing significant weight.
If you look at most popular diets, they generally have the core effect of deemphasizing high glycemic foods from one's diet, usually by shifting calories to meat and/or vegetables.
Personally, I prefer to shift the calories to meat because it's easier to build strength and muscle, when paired with an appropriate physical regimen. In my view, physical strength is an underappreciated and core component of modern fitness.
[1] Slight exaggeration.
good: dietary fat, large portions of pure meat, any sort of meat, all-bacon explosion diet, so-called paleo diet, most popular diets
bad: all the obviously unhealthful foods people don't realize, baked potato (as compared to cake, weight-wise), high glycemic foods
underappreciated and core component of modern fitness: physical strength
Since I started weightlifting, I need the extra energy to keep my weight, and perhaps even gain some.
(self-plug) http://blogriot.com/maintaining-a-food-budget/
One of the benefits of exercising is that once you start doing it regularly, you start to miss it when you stop it. If I don't go for a run every day, I feel it, despite the fact that I hate running.