Normal Weight Obesity, Thin But Too Fat?


If your weight is normal or average, you may feel pretty good about your health. But according to a new Mayo Clinic study, you may look thin but really be too fat inside. You may have what is called normal weight obesity, and if you do, you are at risk for the same problems that are associated with being overweight or obese.

According to the new study, as many as 30 million Americans may mistakenly believe they are at a healthy weight but they really have an unhealthy percentage of body fat. Therefore, a woman whose weight is normal for her height and age but whose body fat is 30 percent or greater would be considered to have normal weight obesity. Among men of normal weight, body fat percentage should be less than 20 to 25 percent or else they are considered to be normal weight obese.

Dr. Jennifer Ashton on CBS News on Wednesday morning reported on the study, noting that people can look normal, even thin, on the outside, but that they can carry around internal fat, also known as visceral fat. Visceral fat is hidden beneath the muscles and surrounds vital organs. This fat is metabolized by the liver, which turns it into blood cholesterol, increasing the risk of heart disease and stroke.

The Mayo Clinic study evaluated 6,171 Americans over a nine-year period and found that 20 to 30 percent of people who are considered to be of normal weight have a dangerously high percentage of body fat. How dangerous? Even though these individuals do not look heavy, they are at greater risk of the same diseases that affect overweight and obese individuals, including high cholesterol, heart disease, high blood pressure, stroke, and diabetes. According to the American Heart Association, heart disease is the number one killer in the United States.


So what should you do? The study’s authors did not recommend that people have their body fat tested, although it certainly is an option for those who want to do so. A simpler and free way to determine if you have too much body fat is to look at your waistline. If you have love handles, you probably have a higher than average amount of body fat.

All is not lost—but you can do something about reducing your risk of life-threatening diseases by losing excess body fat and building lean muscle mass. The Mayo Clinic recently issued The Mayo Clinic Diet, which has two main principles: “Lose It” and “Live It.” It reportedly is “a different approach to weight loss. It’s a lifestyle that can help you maintain a healthy weight for a lifetime.”

Exercise is also necessary to reduce visceral fat. Moderate aerobic exercise most days of the week can help prevent visceral fat from accumulating, while vigorous activity can significantly reduce the amount you already have. Resistance exercises that build lean muscle are also helpful, as muscle burns calories and helps maintain metabolic rate.

Are you among the estimated 30 million Americans who has normal weight obesity? If you are, there are steps you can take to change it, by losing weight and body fat and building muscle. Then you can reduce your internal fat and be as thin on the inside as you are on the outside.

American Heart Association
CBS News, Jan. 27, 2010-01-27
Mayo Clinic