Researchers from Boston University School of Public Health (BUSPH) and the University of Pennsylvania have found that prior studies of the link between obesity and mortality are flawed because they rely on one-time measures of body mass index (BMI) that obscure the health impacts of weight change over time.
The study, published online in the journal Proceedings of the National Academy of Sciences, maintains that most obesity research, which gauges weight at only a single point in time, has underestimated the effects of excess weight on mortality. Studies that fail to distinguish between people who never exceeded normal weight and people of normal weight who were formerly overweight or obese are misleading because they neglect the enduring effects of past obesity and fail to account for the fact that weight loss is often associated with illness, the researchers said.
When such a distinction is made, the study found, adverse health effects grow larger in weight categories above the normal range, and no protective effect of being overweight is observed.
“The risks of obesity are obscured in prior research because most of the studies only incorporate information on weight at a single point in time,” said lead author Dr. Andrew Stokes, assistant professor of global health. “The simple step of incorporating weight history clarifies the risks of obesity and shows that they are much higher than appreciated.”
To read more about the study, go to: http://www.bu.edu/sph/2016/01/04/effects-of-obesity-on-death-rates-understated-in-prior-research/