Posted - February 8, 2010

What is Normal Weight Obesity?

While many fitness and nutritional experts use a body mass index to determine what your normal weight range should be, BMI may miss part of the picture. As a result, you may be within a “normal” weight range and also be considered obese.

People who have a BMI between 18 and 25 but still have enough excess body fat to be considered obese suffer from a condition known as normal weight obesity. While your body mass index may indicate that your weight is normal, BMI only takes into account your height and weight; it doesn’t factor in your actual body fat. Obesity is actually defined as having an excess of body fat, which is not necessarily linked to how much you weigh.

Some guidelines suggest that a woman should have a body-fat percentage of less than 30%. Men’s bodies, on the other hand, should only consist of 20 or 25% fat. Anything over those percentages, regardless of your actual weight, would be classified as obese.

People who have normal weight obesity are at risk for the same health complications as people with classic obesity. An excess of body fat puts you at increased risk for heart disease, diabetes, stroke, and metabolic disorders.

How prevalent is normal weight obesity?

If your body-fat percentage is higher than healthy limits, you could be considered obese, even if your weight or body mass index falls within normal ranges. Women with a body fat percentage above 30% and men with a body fat percentage above 25% are generally considered obese. If you’re obese but manage to have a body mass index between 18 and 25, you’re considered to have normal weight obesity.

One study estimated that more than half of American adults considered to be of a normal body weight have high body-fat percentages that would constitute normal weight obesity. The danger is that a focus on “normal weight” as a protective measure against heart disease, diabetes, and metabolic disorders may be lulling many of these people into a false sense of security.

Are you at risk for normal weight obesity?

The most accurate way to assess your risk for obesity-related health complications is to have your body-fat percentage tested. Your doctor should be able to conduct this test in the office. If you are found to have normal weight obesity, your doctor will likely recommend that you get more physical activity and change your diet to include less fat and calories.