Although simply being overweight is not a disorder of the same caliber as anorexia and bulimia, it's still a major health problem and a cause of concern and frustration for millions of Americans. If you have trouble keeping your weight down, you're far from alone. About a third of the population is technically classified as "obese."

The Official Definition

Medically speaking, obesity is not just another word for "fat." To be considered obese, you must weigh at least 20 percent more than the norm for a woman of your height and bone structure. What's more, there are four grades of obesity. If you are 20 percent heavier than your ideal weight, you are slightly obese. At 40 percent above normal you are moderately obese; at 50 percent, morbidly obese; and at 100 pounds or more over the weight you should be, you are hyperobese.

Doctors worry about obesity because it is a contributing factor in a variety of dangerous medical conditions including diabetes, high blood pressure, and heart disease.