The international collaborative study led by a Mayo Clinic researcher looked at data from 11 different cohort studies from more than 600,00 people from around the world.
- Men with waists 43 inches or greater in circumference had a 50 percent higher mortality risk then men with waists less than 35 inches which translates 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 percent higher mortality risk than women with a waist circumference of 27 inches or less. This translated to about a five-year lower life expectancy after age 40.
- Risk increased in a linear fashion for every two inches of greater circumference mortality risk went up about seven percent in men and about nine percent in women. There was no natural outpoint for waist circumference that could be used in the clinic as risk increased across the spectrum of circumferences.
- 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. BMI is not a perfect measure, said lead study author and Mayo Clinic epidemiologist James Cerhan, M.D., Ph.D. It doesnt discriminate lean mass from fat mass and it also doesnt 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. The primary goal should be preventing both a high BMI and a large waist circumference. For those patients who have a large waist, trimming down even a few inches through exercise and diet could have important health benefits.
Metric For Obesity Strongly Correlated To Premature Death
In 2012, researchers announced development of a new metric to measure obesity A Body Shape Index (ABSI) that combines the existing metrics of Body Mass Index and waist circumference. It also shows a better correlation with death rate than either of these measures individually.
The full results were reported in the open access journal PLoS ONE. The work was led by Nir Krakauer of City College in New York.
The authors took a look at data from over 14,000 U.S. adults taken as part of the National Health and Nutrition Examination Survey and conclude that the new measures which have little correlation with height, weight or BMI appears to be a substantial risk factor for premature death.
Measuring body dimensions is straightforward compared to most medical tests, but its been challenging to link these with health, Krakauer said. Our results give evidence that the power-law scaling of waist circumference, weight, and other body measurements can be used to develop body shape indices that point to added risk.