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.
"If you have a normal weight, don't feel that everything is just
OK," Lopez-Jimenez said. "If you have an excess amount of fat, you
might have metabolic abnormalities as well," he said.
One expert agrees that normal body weight is not synonymous with
good health.
"Body weight is a very blunt instrument; it is not a reliable
gauge of obesity, or health, at the individual level," said Dr.
David L. Katz, director of the Prevention Research Center at Yale
University School of Medicine. "For example, a muscular man may
have a very high body weight, yet be perfectly fit and healthy.
Many people whose body weight is in the normal range are anything
but."
And some people are vulnerable to weight gain in all the wrong
places, such as in and around the vital organs of the abdomen,
notably the liver, Katz said.
"Even a small amount of extra fat where it matters most can
wreak metabolic havoc, increasing risk for diabetes and heart
disease, while leaving you with a body weight that looks perfectly
innocent," Katz said. "Excess body fat in the belly is a menace,
whatever your weight. This study should sensitize patients and
providers alike to this concern."
More information
For more about metabolic syndrome, visit the
U.S. National Library of Medicine.
