CHICAGO (AP) — If you are feeling a bit big
around the waistline, take note: Belly bulge can be deadly for older
adults, even those who aren't overweight or obese by other measures.
One of the largest studies to examine the dangers
of abdominal fat suggests men and women with the biggest waistlines
have twice the risk of dying over a decade compared to those with the
smallest tummies.
"Even if you haven't had a noticeable weight
gain, if you notice your waist size increasing that's an important
sign," said lead author Eric Jacobs of the American Cancer
Society, which funded the study. "It's time to eat better and start
exercising more."
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 bigger waistlines than recommended. And
it's a growing problem: Average waistlines have expanded by about one
inch (2.5 centimeter) per decade since the 1960s.
To check your girth, wrap a tape measure around
your waist at the navel. No fair sucking in your bulge. Men should have a
waist circumference no larger than 40 inches (100 centimeters). For
women, the limit is 35 inches (90 centimeters).
The new study, appearing in Monday's Archives
of Internal Medicine, is the first to analyze waist size and deaths
for people in three BMI categories: normal, overweight and obese. In all
three groups, waist size was linked to higher risk.
About 2% of people in the study had normal BMI
numbers but larger than recommended waists. 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. Study participants measured their own waists, so some
honest mistakes and wishful fudging could have been included, the
authors acknowledged.
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.
People with bigger waists had a higher risk of
death from causes including respiratory illnesses, heart disease and
cancer.
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.
Some older adults gain belly fat while they lose
muscle mass, Jacobs said, so while they may not be getting heavier,
they're changing shape — and that's 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," Jacobs 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.
But Dr. 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. That may mean it's simply a stand-in for some other
culprit that is causing both belly fat and poor health. Klein wasn't
involved in the new research.
Klein said the new study, while showing a link
between waist size and mortality, doesn't pinpoint exactly how much
belly fat is dangerous for normal, overweight and obese people. The
40-inch (100-centemeter) for men and 35-inch (90-centemeter) for women
cutoff points are irrelevant for many people, he 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," Klein said.