Your belly fat could be killing you.
A new study has found that normal weight people with flabby midsections were twice as likely to die from heart disease as obese individuals whose fat was distributed throughout their bodies. The study was published Monday in the Annals of Internal Medicine.
The size of the effect was unexpected even by the researchers.
“I was surprised, particularly in comparison with the obese individuals,” said study coauthor Dr. Francisco Lopez-Jimenez, director of preventive cardiology at the Mayo Clinic. “I anticipated that having normal weight with central obesity would be a risk factor when compared to those with a normal BMI and a normal fat distribution, but to see it was a risk factor, even compared to those with high BMIs, came as a surprise.”
Even more surprising, perhaps, was the fact that thin people with thick midsections were at greater risk of dying than those who were obese.
To put the effect in perspective, Lopez-Jimenez said that being normal weight with midsection obesity was comparable to smoking a half to a full pack of cigarettes daily.
Lopez-Jimenez and his team pored through data from 15,184 people who participated in the NHANES III survey. Along with other data, NHANES researchers collected physical information including waist and hip measurements, weight, and height. During more than 14 years of follow-up, there were 3,222 deaths in the group.
The fat that kills
Why would someone who was obese have a lower risk of dying from heart disease compared to those who are normal weight but carry some extra baggage around their midsections? Lopez-Jimenez suspects it’s because the fat that is in our midsections is especially toxic. Fat in other spots, like the hips and the legs, for example, may actually have a positive effect that ameliorates the damage done by the midsection flab, he said.
That makes sense to Dr. Mitchell Lazar, director of the Institute for Diabetes, Obesity and Metabolism at the University of Pennsylvania. “There’s a lot of evidence that this fat, the visceral fat, is different from other fat,” Lazar said. “The substances that these fat cells spew out go directly to the liver where they have a bigger effect.”
The midsection flab is associated with a host of metabolic issues, including impaired glucose tolerance, low levels of HDL cholesterol and high triglycerides, said Dr. Vicky March, director of the Comprehensive Weight Loss Program at the Magee-Womens Hospital of the University of Pittsburgh Medical Center.
It’s also a sign that the person has lower muscle mass than would be healthy, she said. “You want to have a higher percentage of lean mass and lower fat mass,” she added. “Lean mass is a predictor of being healthy.”
And that’s why one of the recommendations for combating midsection flab is working out, both with aerobic exercise and weight lifting.
Along with that, it might be a good idea to cut out as much sugar as you can from your diet.
“There are studies that suggest that diets rich in refined carbohydrates may promote the growth of visceral fat,” Lopez-Jimenez said.