Belly bulge deadly even for normal weight
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, the study found.
Surprisingly, bigger waists carry a greater risk of death even for people whose weight is "normal" 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 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 per cent of older women have bigger waistlines than recommended. And it's a growing problem: Average waistlines have expanded by about 2.5 centimetres per decade since the 1960s.
Waist circumference how-to
Body mass index (BMI) and waist circumference (WC) are both used to identify whether you are at increased risk of developing health problems because of your body weight or shape. BMI is based on measurements of height and weight and is not a direct measure of body fat, while waist circumference indicates health risk associated with excess abdominal fat. BMI works better for some ethnic groups than others.
Waist circumference is measured at a point halfway between the hip bone and lowest rib — about five centimetres above the belly button.
Many people think the hip bone they feel toward the front of the body is the top of their hips but it's not. By following this spot upward and back toward the sides of your body you should be able to find the true top of the hip bones.
Wrap the tape measure around you in a circle, making sure it is level all the way around. The tape shouldn't push in or indent the skin. Relax, take two normal breaths, exhale, and then take the measurement. It's best to take the measurement on bare skin. If you wear clothes, measure it the same way each time.
A waist circumference of more than 102 centimetres (40 inches) for men and more than 88 centimetres (35 inches) for women is associated with increased risk of Type 2 diabetes, coronary artery disease and hypertension.
A healthy waistline is 94 centimetres (37 inches) for most men and 80 centimetres (31.5 inches) for women. Health Canada recommends measuring waist circumferences for adults with a BMI between 18.5 and 34.9 to prevent and manage obesity.
Sources: Health Canada, Alberta Health Services, Heart and Stroke Foundation of Canada, Canadian clinical practice guidelines in management and prevention of obesity
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 or 102 centimetres. For women, the limit is 35 inches or 88 centimetres.
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.
Bigger waists risky
In all three groups, waist size was linked to higher risk. About two per cent 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.
Fat location
Four extra inches or 10 centimetres around the waist increased the risk of dying from between 15 to 25 per cent. Oddly, the strongest link — 25 per cent — 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.
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.