Washington: Having a big belly is detrimental to your health, even if you have a healthy body mass index (BMI), a new study has warned.
The international collaborative study led by a Mayo Clinic researcher found that men and women with large waist circumferences were more likely to die younger, and were more likely to die from illnesses such as heart disease, cancer and respiratory problems.
The researchers accounted for body mass index, smoking, alcohol use and physical activity.
They 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 per cent higher mortality risk than men with waists less than 35 inches, and this translated to about a three-year lower life expectancy after age 40.
Women with a waist circumference of 37 inches or greater had about an 80 per cent 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.
Importantly, risk increased in a linear fashion such that for every 2 inches of greater circumference, mortality risk went up about 7 per cent in men and about 9 per cent in women.
Thus, there was not one natural "cutpoint" for waist circumference that could be used in the clinic, as risk increased across the spectrum of circumferences.
Another key finding was that elevated mortality risk with increasing waist circumference was observed at all levels of BMI, even among people who had normal BMI levels.
Because of the large size of this pooled study, researchers were able to clearly show the independent contribution of waist circumference after accounting for BMI, said James Cerhan, a Mayo Clinic epidemiologist and lead author of the study.
"BMI is not a perfect measure. 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," he said.
The study is published in the journal Mayo Clinic Proceedings.