Your body mass index (BMI) is a helpful tool to measure how under- or overweight you are—but may be of little use when it comes to determining potentially serious health risks. Researchers have found that individuals with a normal weight BMI, but a higher waist-to-hip ratio, face a higher risk of death—especially death from a cardiovascular disease.
In a new study published online (paywall) Nov. 9 at the Annals of Internal Medicine, an international team of medical researchers take a closer look at what they call “central obesity,” referring to packing extra weight around the midsection. (This is sometimes referred to as “apple-shaped,” as opposed to “pear-shaped” to describe people who are heavier around the hips and legs than in the upper body.)
To examine the link between body shape and mortality, they studied a sample of 15,000 American adults, who had their BMI and waist and hip circumferences measured in a national health survey, and tracked mortality rates in the group over 14 years.
What they found was that men who were normal weight, but had central obesity, had a higher mortality rate than men with any other combination of BMI and waist-to-hip ratio. Similarly, women with a normal-weight BMI, but with central obesity, were more likely to die during the 15-year-period than women who with a similar BMI, or women who were simply obese.
Another notable and worrisome statistic was that heart disease was much more prevalent among women with central obesity than not—normal-weight women with central obesity were twice as likely to die of cardiovascular causes than women with a similar BMI.
The BMI has come under fire in recent years for not being all that useful–but this study, led by Mayo Clinic specialist Dr. Francisco Lopez-Jimenez, underlines how misleading the measure can be when it comes to predicting serious health risks. Lopez-Jimenez told the LA Times that it “is not really telling you the whole story in individual patients.”