Belly Fat

A new study reports that even normal-weight people with belly fat and heart disease have an increased risk of death compared to folks whose fat is concentrated elsewhere.

Belly fat is as significant a risk factor as smoking a pack of cigarettes a day or having very high blood cholesterol, the study said. And the risk is greater for men.

That spare tire is even more significant than your overall body mass index (BMI, a ratio of weight to height) in predicting risk of death, the researchers said, noting their findings discount a puzzling theory known as the "obesity paradox." That surprising finding from earlier studies linked a higher BMI and coronary artery disease with better survival chances than normal-weight people.

BMI is just a measure of weight in proportion to height. What seems to be more important is how the fat is distributed on the body," she said in a clinic news release.

The study is published in the May 10 issue of the Journal of the American College of Cardiology.

The researchers looked at data from five studies conducted around the world, involving almost 16,000 people with coronary artery disease. The risk of death was nearly doubled for people with coronary artery disease and central obesity, which was determined by waist circumference and waist-to-hip ratio, the study found.

What exactly is the difference between belly fat and thigh fat, for instance?

"Visceral [belly] fat has been found to be more metabolically active," Dr. Francisco Lopez-Jimenez, the study's lead investigator and director of Mayo's Cardiometabolic Program, explained in the news release. "It produces more changes in cholesterol, blood pressure and blood sugar. However, people who have fat mostly in other locations in the body, specifically the legs and buttocks, don't show this increased risk."