Obesity Levels Off; Complacency Threatens to Reach Alarming Levels

Last year I noted that the prevalence of obesity among children and teenagers, after tripling between the '70s and the '90s, has leveled off at around 16 percent since 1999. Today The Wall Street Journal's "Numbers Guy," Carl Bialik, points out  that similar trends have been documented in Australia, France, Switzerland, Sweden, and New Zealand:

Obesity rates could have hit a plateau, some scientists propose, if only a certain percentage of children are genetically predisposed to obesity, and that share has gotten fat already. Timothy Olds, a professor of health sciences at the University of South Australia, believes genetics could play a role, but he also points to "all the little things people are doing to encourage healthy weight."

Some researchers argue the data used to produce these conclusions are flawed. And other scientists say that while the methodology of the recent batch of studies appears sound, the findings aren't definitive. Future surveys using different methodologies, they say, could show obesity rates on the move again.

Or so they hope. The disappointment among professional fat alarmists about recent weight data, which suggest the obesity rate has leveled off for American adults as well as children, is palpable. Bialik reports that William Dietz, director of the Division of Nutrition, Physical Activity, and Obesity at the U.S. Centers for Disease Control and Prevention, was "surprised" by the failure of Americans to continue getting fatter, inasmuch as "prominent anti-obesity-awareness campaigns have only been around for a few years." Note the implication that government intervention is the only plausible explanation for changes in human behavior. "What I worry about is that people will read these numbers and think we've got this solved," says Dietz. "I'm encouraged by the results, but this is no time for complacency." Or for budget cutting. Such anxieties underlie press releases with headlines like "New CDC Study Finds No Increase in Obesity Among Adults; But Levels Still High," which are reminiscent of statements from the Office of National Drug Control Policy about the latest drug use survey data. 

As I noted in my 2008 review of Gina Kolata's book Rethinking Thin, research indicating that extra pounds are far less lethal than we'd been led to believe raised a similar alarm among fat warriors. They resisted a downward revision in the death roll attributed to obesity not because it was scientifically unjustified but because it sent the wrong message. Likewise, they argued that it was reckless to publish a study showing that people in the "overweight" (but not obese) range seem less prone to fatal diseases than people in the "healthy" range. "Your patients likely did not read the original article," said an editorial in the journal Obesity Management, "but they did likely hear about it in the news and the message they got was not to worry so much about overweight and obesity. I do not think this is the message you want them to have."

It's possible, of course, that American corpulence will resume its upward climb after resting for a while and catching its breath. But the latest numbers from the National Health and Nutrition Examination Survey (for 2007–2008) should be released this fall, and Dietz presumably has had a peek at them by now. If they included any satisfyingly alarming news, he probably would not be worrying so much about complacency.

My 2004 Reason article about the War on Fat (surely a classic by now) is here.