Decades of research has found strong links between being apple-shaped (due to the accumulation of belly fat) and a higher risk of both cardiovascular disease and type 2 diabetes, compared to being pear-shaped (heavier around the hips and thighs).
But a just-released study published in the Journal of the American Heart Association reveals that women are even more at risk from an apple-shaped physique than men are.
The researchers looked at heart disease risk in more than 500,000 women and men age 40 to 69 whom they followed for seven years. They measured body mass index (BMI), waist circumference, and waist-to-hip ratio (waist circumference divided by hip circumference), among other things.
“The new finding of our study is that the extent to which waist-to-hip ratio is associated with risk of heart disease is greater in women than in men,” says Sanne Peters, Ph.D., research fellow in epidemiology at the George Institute for Global Health at the University of Oxford in the U.K. and lead author of the study.
“We found the risk increased consistently as the ratio increased,” he says. Even among those people with the lowest waist-to-hip ratio, every 0.09 increase—say from 0.82 to 0.91—boosted the risk of heart attack in women by 50 percent. For men, the risk rose by 36 percent. In women, having a higher waist-to-hip-ratio resulted in a 10 to 20 percent higher risk for heart disease than having a higher BMI.
However, the overall odds of having a heart attack in people aged 40 to 69 are still low. Just 1.8 to 4.2 percent of women and 3.3 to 11.3 percent of men in this age group have a heart attack, according to data from the National Health and Nutrition Examination Survey.
A waist to hip ratio greater than 0.85 in women and 0.9 in men is an indication of abdominal obesity, according to the World Health Organization. But given the results of this study, even if your waist-to-hip ratio is below those levels, you may be increasing your risk with every incremental gain in abdominal fat.
The Trouble With Belly Fat
Belly fat, technically called visceral fat, is located deep in the abdominal cavity where it surrounds organs such as the liver and pancreas. This means that the fat can trigger a variety of metabolic changes, including increased insulin resistance and higher triglyceride levels.
In contrast, the fat that settles around the hips and thighs—called subcutaneous fat—lies just under the skin and isn’t linked to such changes.
Women may be more vulnerable than men to storing fat in their abdomens due to hormonal and other age-related changes. A study published in the journal Obesity in 2015 found that during midlife, women gain an average of 4 percent of belly fat per year.
“It’s sneaky because the scale might not be changing, but fat can be redistributed even without any weight gain,” says Rasa Kazlauskaite, M.D., an endocrinologist at Rush University Medical Center in Chicago. And previous research suggests that genes associated with cholesterol and triglycerides and insulin resistance may be more affected by abdominal fat in women than in men.
How to Get Rid of Belly Fat
While genetics may partly dictate where you store fat, lifestyle also plays a role. And that means there are several changes you can make that can help decrease your waist-to-hip ratio, and with it, your risk of heart disease.
• Eat more whole grains. A 2010 study published in the American Journal of Clinical Nutrition found that those who consumed three or more daily servings of whole grains had 10 percent less visceral abdominal fat than those who ate virtually no whole grains.
But you need to choose all your grains carefully to see these effects. The study also found that eating four or more servings a day of refined grains negated any belly fat benefits of whole grain consumption.
• Focus on healthy fats. Eating more poly- and monounsaturated fats and fewer saturated fats can help reduce your waistline. These healthier fats have anti-inflammatory effects that help better regulate insulin and result in less fat stored in the abdomen. You’ll find them in fish, nuts, and vegetable oils, such as olive oil.
• Exercise regularly. A 2016 review of 117 studies found that while diet caused more weight loss than exercise, being active (even without weight loss) was related to a 6.1 percent decrease in visceral abdominal fat.
And there’s some recent evidence that high intensity interval training (HIIT), in which you do short bursts of activity at close to your peak heart rate followed by easier bouts, could be particularly effective at banishing belly fat, too.
“We’ve seen greater abdominal and visceral fat loss with HIIT than with moderate-intensity continuous exercise,” says Nathalie Boisseau, a professor of sports physiology at Université Clermont Auvergne in France. “The mechanisms are not known, but HIIT does promote greater fat oxidation during the recovery period.”
• Manage your stress. Observational studies that measure levels of cortisol (the stress hormone) in saliva have found a connection between higher levels and increases in both BMI and abdominal obesity.
• Get more sleep. Research has shown that sleeping less can lead to weighing more, but a 2011 study published in the journal Clinical Obesity also found that those who slept six hours or less per night tended to put on that excess weight primarily around their middle.
