HAVING a little paunch is just no good with a Speedo or bikini. Health-wise, it's none too pretty either.
That bulge is the outward sign of a deeper problem: visceral fat, a kind of biological monstrosity that, in excess, wreaks havoc on the body, raising the risk for heart disease, diabetes, possibly even dementia and some types of cancer.
Lying deep inside the body, wrapping around the liver and other major organs, visceral fat acts like a kind of organ itself -- spewing out bad hormones and squashing the production of good ones. It sets up the body for sickness as the years roll by and additional fat accumulates.
"Visceral fat is very bad for you," says Richard N. Bergman, a professor at USC's Keck School of Medicine. "It seems to have a more negative outcome on health than overall fat."
The evidence now is so compelling that some experts suggest it's time to forget about scales and weight loss and focus on waists and "inch loss."
Luckily, visceral fat doesn't appear to be a particularly stubborn enemy. Health experts have discovered that consistent, moderate exercise by itself appears to help the body rid itself of vast amounts of deep abdominal fat -- even when the scales show the pounds aren't dropping very fast.
This emerging science carries a message for consumers: Measure your waist circumference. And reduce it if need be. Doing something about that paunch could help save your life.
Recent studies on visceral fat help explain a well-established fact: that having a pear shape is more healthful than having an apple shape. A pear shape is caused by subcutaneous fat resting just under the skin. Apple is caused by the deep, visceral fat. What this means is that although both types of people -- apple and pear -- can be overweight, the person with the apple shape has more health risks.
It also means that people with normal weight can be at a higher health risk without realizing it.
Most people gain abdominal fat with age, but research shows the tendency to put on weight around the middle may be inherited. A study published this month in the Proceedings of the National Academy of Sciences identified particular genes that appear to dictate how fat develops and where it's stored.
A long list of illnesses
Meanwhile, the evidence for visceral fat's ill effects is mounting.
In research published in November in the Lancet, doctors concluded that a person's waist measurement is a more accurate predictor of heart attack than the body mass index, or BMI, which is a weight-to-height ratio.
Analyzing data from 27,000 people in 52 countries, the scientists found that BMI measurements were only slightly higher among people who had had heart attacks compared with those who hadn't. But heart attack sufferers had a much higher waist-to-hip ratio (a measurement that reflects abdominal fat) compared with those who hadn't, regardless of other cardiovascular risk factors. This finding was true for men and women in every ethnic group.
"This was the first study that really documented this relationship across all ethnic groups," says Dr. Arya M. Sharma, a co-author of the study from McMaster University in Hamilton, Ontario, Canada, and director of the Canadian Obesity Network.
Other studies have linked visceral fat to metabolic syndrome -- a grouping of risk factors, such as high cholesterol and high blood pressure, that can precede diabetes and heart disease. For example, Wake Forest University researcher Barbara Nicklas published a study in 2004 showing that among overweight, post-menopausal women, those with the most abdominal fat were the most likely to have metabolic syndrome.
Additional illnesses may be influenced by excess abdominal weight too. A Kaiser Permanente study presented earlier this year at an obesity conference showed that people with the most abdominal fat were 145% more likely to develop dementia compared with people with the least amount of abdominal fat.
Research has also linked deep abdominal fat to the development of gallstones and breast cancer in women and overall risk of premature death in men. In a study of 291 men published online earlier this month in the journal Obesity Research, doctors found that men with more abdominal fat died in greater numbers, independent of all other risk factors the scientists examined. A man with 2.2 pounds of visceral fat has double the risk of death compared with a man with 1.1 pounds of fat.
Fat's harmful factors
Experts aren't sure why fat can be bad in one area of the body and yet not so bad in others. But they have two strong theories. One has to do with what visceral fat does. The other has to do with where it's located.