Contrary to previous medical assumptions about the correlation between higher weight and increased mortality rates, a study published in the Journal of the American Medical Association draws on data from Centers for Disease Control and Prevention (CDC) to show that people in the study considered "overweight" (defined by the CDC as having a Body Mass Index of 25 to 30) actually lived longer on average than people considered to have a "normal" weight or to be "underweight."

While people considered "obese" (having a Body Mass Index of >30) do die at higher rates than these other groups, the study shows that this discrepancy is only a fraction of what was estimated in a debunked study released by the Centers for Disease Control and Prevention the previous year. And debates remain over whether these deaths are caused by "obesity" itself or by specific conditions like diabetes and heart disease that are common but not ubiquitous across higher weight groups.