Have you heard the one about the fat-burning grapefruit? Or the Chinese magic weight-loss earrings? Have you tried a get-thin-quick scheme or two yourself? Then you've been "myth-taken"! Diet gimmicks waste your money because they don't work. Some are just plain silly and some are downright unsafe. Here are the facts about five popular weight-loss fads.

Fad: Fasting is a quick, effective way to take off pounds.

Fact: Quite the contrary. Fasting for long periods is not only dangerous but is counterproductive. Any quick weight loss you see is mostly from water and muscle tissue, not body fat. Going without food for long periods deprives you of energy and nutrients. It also slows down your metabolism so you burn fewer calories—not a desirable consequence!

Fad: Try the Cabbage Soup Diet. The more soup you eat, the more weight you'll lose.

Fact: On this seven-day diet you fill up on all the cabbage soup you want, while other foods are strictly limited. There's no magic about cabbage soup. If you lose weight, it's only because you're eating fewer calories. This diet is nutritionally unbalanced and doesn't teach healthful, new habits, so you'll most likely gain back any weight you lose.

Fad: Chromium supplements stimulate your body to use stored fat, so you can eat whatever you want and still lose weight.

Fact: Pills—including chromium supplements—can't stimulate your body to burn fat. Most people get all the chromium they need from food. Taking extra chromium in pill form doesn't appear to offer any benefits, and it may cause harm.

Fad: A high-protein, low-carbohydrate diet triggers quick weight loss by causing the body to burn stored fat for fuel.

Fact: Rapid weight loss on this diet is mostly from water, not body fat. Depriving the body of fuel from carbohydrates can cause nausea, weakness, breakdown of muscle, dehydration, and stress on the kidneys, all of which are potentially dangerous. Because this diet forbids almost all grains, fruits, and vegetables, you'll come up short on vitamins, minerals, and fiber.

Fad: Diet pills are an easy way to take off excess pounds.

Fact: Over-the-counter diet pills curb your appetite, but they only work for a few weeks. Some pills may cause unpleasant—or even dangerous—side effects. Consult your doctor with questions about over-the-counter or prescription diet aids.