When you think "fad diet," you probably think of things exactly like this: the cabbage soup diet, a menu plan that has you forgoing almost all foods except, of course, cabbage soup. There's no denying you'll lose weight -- dieters report losing as much as 10 pounds (4.5 kilograms) in only a week -- but there are problems with this plan.
First, imagine eating cabbage soup for all your main meals for seven days; it's a tedious and uninspired menu. And second, it's not healthy weight loss. In the long run, eating nothing but cabbage soup (and maybe a little bouillon, black coffee, or a tomato) may give you good results for the week you follow the menu, but these are not the foods of a balanced diet. This diet is low calorie, low fat, low protein, and low on essential nutrients, so the weight you do lose is really nothing more than fluids -- water retention -- rather than fat. So? That means as soon as you return to eating real foods again, you'll still be trying to find ways to lose that belly fat.