Journal of the American Medical Association Suggests Being Overweight or Grade-1-Obese is Not Correlated with Increased All-Cause Mortality Risk
By Adam Brown
The Journal of the American Medical Association (JAMA) published a controversial meta-analysis suggesting that people who are overweight (a body mass index [BMI] of 25-30 kg/m2) or class I obese (a BMI of 30-35 kg/m2) do not have a higher mortality risk than those at a normal weight (a BMI less than 25 kg/m2). The study also demonstrated that a BMI of 35 kg/m2 or greater was associated with a significantly higher risk of mortality. The meta-analysis evaluated an impressive 97 studies with data from nearly three million people and more than 270,000 deaths. These findings are certainly contentious, and in our view, represent additional evidence that BMI alone is an inaccurate indicator of overall health.
Along with the meta-analysis’ publication was an editorial by Drs. Steven Heymsfield and William Cefalu that considered other indices when evaluating a person’s health. Previous studies that investigated BMI and risk of mortality showed similar results to this meta-analysis: a 2005 study found no increased risk for people who are overweight, while a 2010 study found a decreased relative mortality risk for people who are overweight.
Unfortunately, while it is easy to calculate, BMI is not a holistic descriptor of an individual’s health. Importantly, it does not include information such as abdominal fat pattern, muscle mass, blood pressure, blood lipid levels, and fasting blood glucose levels – all important contributors to someone’s overall health. For instance, a top athlete with lots of muscle mass might have a BMI in the overweight or obese category, even though they are in tip-top shape. As a result of these limitations, we would interpret these study results cautiously, and encourage readers to speak with their healthcare team about the benefits of maintaining a healthy weight. –MN/AB