Having a big belly could be detrimental to one's health, even if they have a healthy body mass index (BMI), according to a recent study.

Researchers found that men and women with large waist circumferences are more likely to die younger, and are more likely to die from illnesses such as heart disease, respiratory problems, and cancer after accounting for smoking, alcohol use and physical activity. They said big belly's pose a threat regardless of BMI.

"BMI is not a perfect measure," James Cerhan, lead author of the study, said in a statement. "It doesn't discriminate lean mass from fat mass, and it also doesn't say anything about where your weight is located. We worry about that because extra fat in your belly has a metabolic profile that is associated with diseases such as diabetes and heart disease."

For the study, researchers pooled data from 11 different cohort studies, including more than 600,000 people from around the world.

They found that men with waists 43 inches or greater in circumference had a 50 percent higher mortality risk than men with waists less than 35 inches. That translated to about a three-year lower life expectancy after age 40.

Researchers found that women with a waist circumference of 37 inches or greater had about an 80 percent higher mortality risk than women with a waist circumference of 27 inches or less, and this translated to about a five-year lower life expectancy after age 40.

They also found that the risk increased in a linear fashion such that for every 2 inches of greater circumference, mortality risk went up about 7 percent in men and about 9 percent in women.

Cerhan suggests physicians consider both BMI and waist circumference as part of risk assessment for obesity-related premature mortality.

"The primary goal should be preventing both a high BMI and a large waist circumference," Cerhan said. "For those patients who have a large waist, trimming down even a few inches - through exercise and diet - could have important health benefits."