Normal Weight Doesn't Always Equal Healthy Weight

TUESDAY, April 1 (HealthDay News) -- Despite appearances to the contrary, more than half of normal-weight Americans have a high percentage of body fat. And, like their overweight contemporaries, this makes them susceptible to heart disease, diabetes and other metabolic disorders, a new study says.

Men whose body fat is greater than 20 percent and women whose body fat is greater than 30 percent are suffering from "normal weight obesity," the study authors said, even though their weight may be normal for their size.

"The prevalence of people with a high amount of body fat despite a normal weight is relatively high," said lead researcher Dr. Francisco Lopez-Jimenez, a cardiologist with the Mayo Clinic in Rochester, Minn. "Many of these people have metabolic abnormalities."

These findings should alert doctors that body weight isn't the only way to protect against health problems caused by excess pounds, Lopez-Jimenez said. Even normal-weight people should be advised to exercise and eat a healthful diet to reduce their level of fat, especially belly fat, he added.

The findings were expected to be presented Tuesday at the American College of Cardiology's annual meeting, in Chicago.

For the study, Lopez-Jimenez and his colleagues collected data on 2,127 people who participated in the U.S. government's Third National Health and Nutrition Examination Survey. Specifically, the researchers looked at risk factors for heart disease, diabetes, and metabolic syndrome, a precursor of diabetes.

The researchers found that 61 percent of the participants had levels of body fat that indicated "normal weight obesity." In addition, Lopez-Jimenez's group found changes in blood chemistry that can affect heart and metabolic health, including high cholesterol; high levels of leptin, a hormone found in fat and other tissues that's involved in appetite regulation; and high rates of metabolic syndrome.

Lopez-Jimenez said the study shows that just because your weight may be normal for your size, it doesn't mean you aren't at risk for heart disease and diabetes.