Rely less on your bathroom scale and more on your tape measure.
A new study has found that having a too-big waistline is associated with an increased risk of premature death — no matter what weight category (normal, overweight or obese) your body mass index (BMI) puts you in.
Specifically, the study found that men with a waist size of 47 inches or larger and women with a waist size of 41 inches or larger were twice as likely to die prematurely than people with smaller waists (35.4 inches for men and 29.5 inches for women).
And here’s a surprising (and troubling) finding: The association was strongest for women with a normal BMI. Their risk of dying increased by about 25 percent for each 4 inches of extra (above 29.5 inches) waistline body fat.
In this study, which followed more than 100,000 men and women aged 50 and older for nine years, waist circumference was most strongly associated with death caused by respiratory disease, heart disease and cancer (in that order). Other studies have linked a large waistline with a greater risk of developing type 2 diabetes.
Why might a large waistline increase the risk of disease even in normal-weight (as determined by BMI) people? Scientists aren’t sure, but they think visceral fat (the kind that surrounds your internal organs in the abdomen) may be more harmful than subcutaneous fat (the kind that lies just under the skin). Visceral fat has been associated with increased inflammation, insulin resistance, higher cholesterol and other markers of poor health.
And that’s not good news for older Americans. As the authors of this study, which was published Monday in the Archives of Internal Medicine, note, some 50 percent of men and 70 percent of women in the U.S. between the ages of 50 and 79 years have waistlines that “exceed the threshold for abdominal obesity.”
Of course, like all studies, this one has its limitations. Most notably, it relied on the participants’ self-measurements of their waistlines. And because of the way the study is designed, it’s only able to show an association, not a cause-and-effect, between waist circumference and premature death.
Still …. Other studies have made similar findings. As the authors of this study note, the National Institutes of Health’s current clinical guidelines for determining obesity, which were devised in the 1990s, may be out-of-date. Your waistline may be a much better predictor of future health problems than your BMI.
So, get out your tape measure. But here we run into a problem. What is a “healthy” waistline? In the current study, the association between belly fat and premature death was linear, suggesting no clear threshold for risk.
In fact, a 2008 European study, which also linked a large waistline with a doubling of risk of dying prematurely, defined “large” and “small” waists differently from this current U.S. study. The Europeans described a large waistline as 47 inches in men and 39 inches in women, while a small waist was 32 and 26 inches in men and women, respectively.
Even with this uncertainly, however, it’s probably a good idea to shed belly fat to at least the current recommended levels. Men: Your waistline should be below 40 inches. Women: Yours should be below 35 inches. Measure just above your navel — and no “cheating” by pulling in your abdomen as you do the measuring.
If you find your measurement exceeds those numbers, then you’ll need to get to work trimming it. For that, you’ll need to take up the usual weight-reducing activities: Cutting back on unnecessary calories and exercising more.
Forget about sit-ups. They’ll tighten your abdominal muscles (a good thing), but they won’t get rid of your belly fat.