Overweight Adults May Have the Lowest Mortality: Do They Have the Best Health?
March 7, 2011 — While overweight adults die at lower rates than other weight categories, a new study shows that higher body weight was consistently associated with worse health risk profiles.
Anna Zajacova, assistant professor in the University of Wyoming Department of Sociology, led the study published in the American Journal of Epidemiology. She analyzed a large representative sample of American adults of all ages to determine how body weight relates to health risks, based on specific biological markers.
"In the popular press, the association between being overweight and lower mortality risk has been generalized to health outcomes, with the implication that carrying extra body weight does not impair health," she says. Zajacova cites a New York Times article that noted "chubby ... may be the new healthy" when reporting on a recent study of body mass index (BMI) and mortality.
The previous studies showed that overweight adults die at lower rates than adults who are underweight, normal-weight or obese. This pattern implies that being overweight (based on guidelines established by the National Heart Lung and Blood Institute and the World Health Organization) is optimal for health. It contradicts the predominant medical and epidemiological messages that adults should try to keep their weight in the normal range.
"Using an innovative analytic approach, the study found that higher body weight was consistently associated with worse health risk profile," Zajacova says. This association occurred among men and women of all ages and held from the lowest to the highest BMIs.
"Our findings were in direct contrast to the patterns reported between BMI and mortality and indicate that mortality results do not generalize to adult health," Zajacova says. "At least for some biological risk indicators, lower body weight is better."
The journal article can be found at http://aje.oxfordjournals.org/content/173/4/430.short .