Walter Willett

Walter Willett

Does being overweight really reduce mortality?

Panelists challenge controversial findings

In a recent paper in the Journal of the American Medical Association that combined the results of many studies of body mass index (BMI) and mortality, Katherine Flegal from the Centers for Disease Control and Prevention and co-authors concluded that, compared with normal weight, being overweight was linked with lower risk of mortality. This report, released in January 2013, received widespread media attention and has led to many questions about the inconsistency of studies on this topic.

A February 20, 2013 panel discussion at Harvard School of Public Health reviewed the overall evidence on body weight and evaluated Flegal’s findings. Flegal was invited to the event but did not attend.

Panelists were critical of Flegal’s methods, which they said resulted in the artificial appearance of a protective benefit from extra weight. They also pointed to a preponderance of evidence demonstrating that overweight increases a person’s risk of developing hypertension and insulin resistance, which can lead to coronary heart disease, stroke, type 2 diabetes, and cancer.

Walter Willett, chair of HSPH’s Department of Nutrition and Fredrick John Stare Professor of Epidemiology and Nutrition, organized the event to help clear up public confusion over the link between health and weight.

It is important for people to have correct information, Willett said. “If you don’t have the right goal you are very unlikely to end up in the right place.”

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Ask the Expert: Does being overweight really decrease mortality? No! (HSPH Nutrition Source)

Photo: Aubrey LaMedica