1. The menu features extremely limited food choices, such as only grapefruits and melon for fruits, or rice and pasta for starches.

2. You must cut out an entire food group, like carbohydrates.

3. You choose your meals from only one food group, maybe all protein or all carbohydrates.

4. The diet eliminates all fats.

5. It promises ultra-fast weight loss, a pound per day or more.

6. The diet is used to sell a product, such as herbal weight-loss pills or a specific food.

7. The weight-loss claims are based on unproven science, such as the idea that combining certain foods can cause you to gain or lose weight.

8. The diet's promoters put down traditional medical experts by saying that doctors don't understand the way the program works.

9.The promoters make claims that sound too good to be true --you can lose weight while you sleep or eat lots of fattening foods and still lose weight.

10. The explanation of how the diet works is simplistic, and promoters say that the true explanation is too complex for most people to understand.