The way in which fat is distributed in your body has major health implications, yet it’s not taken into account by the BMI calculation. Belly fat, or fat that accumulates around the waistline and abdominal organs, greatly heightens a person’s risk of heart disease, type 2 diabetes, and other obesity-related complications, as well as death. But a person could easily fall into the “normal” BMI category (18.5 to 24.9) and have a waist circumference that puts him or her in a risk health category.

Individuals with “normal,” or non-obese/non-overweight BMIs, but with a large waist circumference (known as central obesity) are much more likely to die prematurely compared with people who are deemed obese via BMI but don’t have a large circumference. What qualifies as central obesity?

• A waist circumference greater than 40 inches for men

• A waist circumference greater than 35 inches for women

A 2015 study in the Annals of Internal Medicine confirmed this exact phenomenon when researchers looked at more than 15,000 adults between the ages of 18 and 90 years, all of whom had “normal” BMIs. Those with central obesity had up to twice the risk of dying prematurely as participants who were overweight or obese according to BMI but did not have large waist circumferences.