HEALTH MATTERS : A BIG BELLY BRINGS HIGHER DEATH RISK / THE WALL STREET JOURNAL ( RECOMMENDED READING )

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AUGUST 10, 2010

Study: A Big Belly Brings Higher Death Risk

Belly bulge can be deadly for older adults, even those who aren't overweight or obese by other measures, according to one of the largest studies to examine the dangers of abdominal fat.

The new study, appearing in Monday's Archives of Internal Medicine, suggests men and women with the biggest waistlines have twice the risk of dying over a decade compared with those with the smallest tummies.

Surprisingly, bigger waists carry a greater risk of death even for people whose weight is "normal'' as measured by the body mass index, or BMI, a standard measure based on weight and height.

"Even if you haven't had a noticeable weight gain, if you notice your waist size increasing that's an important sign,'' said the study's lead author, Eric Jacobs, strategic director of pharmacoepidemiology at the American Cancer Society, which funded the study. "It's time to eat better and start exercising more," Dr. Jacobs said.

People with bigger waists had a higher risk of death from causes including respiratory illnesses, heart disease and cancer.

Other research has linked waist size to dementia, heart disease, asthma and breast cancer.

Bulging bellies are a problem for most Americans older than 50. It's estimated that more than half of older men and more than 70% of older women have waistlines that are bigger than recommended. It's a growing problem: Average waistlines have expanded by about one inch per decade since the 1960s.

To check your girth, wrap a tape measure around your waist at the navel; don't suck in your bulge. Men should have a waist circumference no larger than 40 inches. For women, the limit is 35 inches.

The study is the first to analyze waist size and deaths for people in three BMI categories: normal, overweight and obese. Waist size was linked to higher risk in all three groups.

About 2% of people in the study had normal BMI numbers but larger-than-recommended waists. Dr. Jacobs said the risk increased progressively with increasing waist size, even at waist sizes well below what might be considered too large. The study used data from more than 100,000 people who were followed from 1997 to 2006. Nearly 15,000 people died during that time.

The researchers crunched numbers on waist circumference, height and weight to draw conclusions about who was more likely to die.

Four extra inches around the waist increased the risk of dying from between 15% to 25%. Oddly, the strongest link—25%—was in women with normal BMI.

The study was observational, a less-rigorous approach that means the deaths could have been caused by factors other than waist size. But the researchers did take into account other risk factors for poor health, such as smoking and alcohol use. Study participants measured their own waists, so some honest mistakes and wishful fudging could have been included, the authors acknowledged.

Some older adults gain belly fat while they lose muscle mass, Dr. Jacobs said. They may not get heavier, but they are changing shape—and that is taking a toll. A tape measure, or a belt that doesn't buckle the way it used to, "may tell you things your scale doesn't,'' he said.

Fat stored behind the abdominal wall may be more harmful than fat stored on the hips and thighs. Some scientists believe belly fat secretes proteins and hormones that contribute to inflammation, interfere with how the body processes insulin and raise cholesterol levels.
Samuel Klein, an obesity expert at Washington University School of Medicine in St. Louis, is skeptical about that theory. Removing belly fat surgically doesn't lead to health improvements, which may mean it's simply a stand-in for some other culprit that causes both belly fat and poor health. Dr. Klein wasn't involved in the research.

While showing a link between waist size and mortality, the study doesn't pinpoint exactly how much belly fat is dangerous for normal, overweight and obese people. The 40-inch for men and 35-inch for women cutoff points are irrelevant for many people, Dr. Klein said.

What can be done to fight belly fat? It's the same advice as for losing weight. Eat fewer calories and burn more through walking, bicycling and other aerobic exercise. "Sit-ups are useless," Dr. Klein said.

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