Even if you're not overweight, having a large belly raises your risk of dying of heart disease, a new study suggests.

To explore factors linked to early death, researchers relied on body measurements and other health information gleaned from more than 15,000 adults who took part in a national health survey. The average follow-up period was 14 years.

They found that normal-weight people with a "spare tire" (known as central or abdominal obesity) 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. The results, published in the Dec. 15, 2015, Annals of Internal Medicine, suggest that people with central obesity—even if they're not overweight—may benefit from lifestyle changes to prevent heart disease, such as exercise and eating a healthy, plant-based diet.

Central obesity is defined as having a waist-to-hip ratio of greater than 1.0 for men or greater than 0.9 for women. To calculate yours, measure around your waist (just above your belly button) and your hips (around the widest part of your buttocks) and divide the first number by the second.