Belly fat may pose more danger for women than for men

Whittle your waist for better health.

Published: June, 2018

You've probably heard that extra pounds around your middle are bad for your heart. But a new study has found that excess weight in your belly — a body shape doctors refer to as central adiposity — may be even worse for women's heart health than men's.

The study, in the March 6 issue of the Journal of the American Heart Association, involved about 500,000 people (55% of them women), ages 40 to 69, in the United Kingdom. The researchers took body measurements of the participants and then kept track of who had heart attacks over the next seven years. During that period, the women who carried more weight around their middles (measured by waist circumference, waist-to-hip ratio, or waist-to-height ratio) had a 10% to 20% greater risk of heart attack than women who were just heavier over all (measured by body mass index, or BMI, a calculation of weight in relation to height).

Trouble ahead

A larger waist-to-hip ratio, in particular, appeared to be a bigger heart attack risk factor for women than men. The analysis showed that compared with BMI, waist-to-hip ratio was 18% stronger as a heart attack predictor in women — versus 6% stronger in men.

But the message that you should take from this study should be less about the gender differences and more about the overall risks presented by central adiposity, says Dr. Barbara Kahn, the George Richards Minot Professor of Medicine at Harvard Medical School.

Widening waistline, growing risks

Regardless of whether women are more vulnerable than men to heart problems related to abdominal weight gain, it's pretty clear that central adiposity presents important health risks, Dr. Kahn says. Researchers have shown that weight gain around the middle represents an increase in the amount of visceral fat, the type of fat that encases your internal organs. "There are many studies showing that an unfavorable waist-to-hip ratio is highly associated with diabetes and cardiovascular risk," says Dr. Kahn.

One such study, in the Dec. 15, 2015, Annals of Internal Medicine, found that normal-weight people with a "spare tire" had a higher risk of dying of heart disease or any other cause compared with people without central obesity, regardless of whether they were normal weight, overweight, or obese.

So, if your waistband has been feeling a little tighter these days, it may be time to take some action. Below are some strategies you can use to help whittle your waistline and reduce your risk.

Keep weight gain in check. "The focus should be on limiting weight gain over all," says Dr. Kahn. Women tend to put on pounds as they get older and after menopause. This occurs for many reasons, among them hormonal changes, a decline in muscle mass (because fat burns less calories than muscle), and in some cases, lifestyle changes. Keeping tabs on your weight — and your waist — and making changes to your daily routine can help prevent the pounds from creeping up as you go through this transition. (To find out how to measure your waist-to-hip ratio, see "Your health by the numbers: Calculating your risk.") "I don't talk with patients as much about going on a diet as I do about creating a long-term lifestyle program that includes physical activity and sustainable dietary changes," says Dr. Kahn. Weight that comes off slowly tends to stay off. By contrast, very rapid weight loss can trigger your body to slow its metabolism, setting the stage for the weight to be regained quickly.

Get moving. It's probably no surprise that increasing the amount of exercise you do should be a goal if you're looking to keep your waistline in check. "I'm a big proponent of regular exercise," says Dr. Kahn. If you're squeezed for time, fit it in where you can — for instance, a half-hour walk outside the office at noon or before you drive home for the day. "It doesn't have to be excessively vigorous. You don't need to go to the gym and change your clothes," she says. Just being physically active can help improve your metabolic health. Even getting up to walk around periodically during work can be beneficial.

Regular physical activity may not always help you lose weight, but again, it can help you maintain a healthy weight and also improve blood sugar for people with diabetes. Having a higher proportion of muscle mass can help you burn more calories, so adding strength training at least twice a week, focusing on all the major muscle groups, may also help you maintain your weight.

Your health by the numbers: Calculating your risk

Research has shown that a wider waistline can put you at increased risk for cardiovascular disease, but exactly how wide is too wide — and more importantly, are you in the danger zone?

Many people gauge their body size by BMI, a calculation based on both weight and height. You're considered overweight if your BMI is 25 to 29.9, and you meet the definition for obesity if your BMI is 30 or above. (To find out your BMI, use the calculator at www.health.harvard.edu/BMI.)

But BMI doesn't tell the whole story. As a recent study in the Journal of the American Heart Association shows, your waist-to-hip ratio may actually be more important in predicting your heart attack risk.

Here's how to calculate your waist-to-hip ratio:

  1. Measure around the widest part of your hips and the narrowest part of your waist, which is just above your navel. (Ideally a woman's waist measurement should be less than 35 inches to avoid health risks.)

  2. Divide your waist measurement by your hip measurement. You're safest with a waist-to-hip ratio of .85 or below.

Prone to gain?

Unfortunately, avoiding weight gain around the middle may be easier for some women than others, as some people are simply more prone to adding extra pounds in the belly.

Research may one day help to uncover new ways to head off this dangerous type of fat and, in turn, reduce the risk for diabetes and cardiovascular disease. Certain newer medications used to treat people with diabetes — known as sodium-linked glucose transport inhibitors — have the interesting side effect of inducing weight loss and reducing visceral fat, says Dr. Kahn. "This does point to the possibility that there may be some physiological mechanisms that target visceral adiposity," says Dr. Kahn.

One day, medication may help you lose your belly fat, but in the meantime, focus on lifestyle changes and exercise and keep an eye on your belt buckle to gauge your progress.

Image: © KittisakJirasittichai/Getty Images

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