05/09/2005 12:00 am ET Updated May 25, 2011

Media & Public Health: Obesity Wars

"Obesity death toll was vastly inflated" (Seattle Times, April 20)

Senior officials at the U. S. Centers for Disease Control and Prevention (CDC) have had remarkably little to say since April 20 when one of their own research teams published a bombshell study that was widely reported as decimating the agency’s rationale for its war against obesity. The result has been a firestorm of criticism directed at the CDC.

This affair has been an unmitigated disaster--for the CDC’s credibility, for the public’s understanding of science, and for our collective will to address the genuine health threat posed by obesity.

The new study directly contradicts one published last year by a different CDC research team which found that obesity and overweight were responsible for 400,000 deaths each year in the U.S. (corrected downward to 365,000 in January 2005). These figures were used as the basis for a major new campaign announced by then HHS Secretary Tommy Thompson to encourage Americans to cut calories and exercise more.

The new study concludes that obesity is responsible for only 112,000 deaths per year, and reaches the provocative conclusion that individuals who are somewhat overweight but not obese actually have a lower risk of death than people of normal weight, accounting for 86,000 lives saved each year. Subtracting the lives saved (86,000) from the lives lost (112,000),the “net” deaths from overweight/obesity is estimated at only 26,000. As The New York Times put it in a stinging editorial, this study “upends much of what we thought we knew about the health dangers of excess poundage… It leaves the CDC, in particular, with a lot of explaining to do.”

Some journalists and CDC critics have cited the 26,000 figure incorrectly, as the number of deaths from obesity. The 112,000 individuals who lost their lives due to obesity cannot be brought back to life by the sleight of hand of subtracting the 86,000—a different group of people!—who lived longer because they were somewhat overweight but not obese.

So, why didn't the CDC take a stand on the new findings? There was a lot at stake, including one of the CDC’s most precious assets—its credibility as an authoritative and reliable spokesperson for public health. The agency dropped the ball, big time.

Instead of developing a clear position, and holding a press conference to interpret the study and put it in context, the agency settled for a short written statement which offered a cursory summary of the new findings and made no attempt to reconcile them with the CDC’s prior estimates of the obesity epidemic. As a result, individual researchers and reporters were left to fill the void on their own.

The study’s lead author, Dr. Kathleen Flegal, was quoted by The Baltimore Sun as commenting, “I’m not sure what the public should take from [the study.] I don't see it as the final answer to anything.” Most news stories gave short shrift to some top researchers who expressed doubts about the study’s methods. And, a JAMA editorial that urged caution in evaluating the study was virtually ignored by the press. The damage is strewn over the media landscape, with headlines such as "CDC: Obesity isn't as deadly as it was ... in January" and "This"ll kill ya: Packing on pounds may not be so deadly".

It’s true, as the late, esteemed scientist and philosopher Lewis Thomas put it, that "every field of science is incomplete, and most of them - whatever the record of accomplishment during the last 200 years - are still in their very earliest stages." And, it’s true that scientific understanding often is characterized by one step backward and two steps forward. But the long-term trajectory of science is indeed in the direction of forward progress. That perspective is all too easily lost when journalists turn the spotlight on the “latest” twist-and-turn without providing adequate context.

Much of the burden falls on the scientific community-- to improve its communication with reporters and the public, and to present new findings in a fuller context. However, this problem will never be solved to everyone’s satisfaction. The public--and the reporter’s editor--want to know, “Is it safe to be moderately overweight—yes or no? But the scientist’s answer often will be “somewhat” or “maybe.”