A decade-long drumbeat of bad news about childhood obesity is now officially wrong. Michelle Obama is wrong, too. America is not in the grip of a childhood-obesity epidemic and, consequently, the first lady’s much-ballyhooed anti-obesity strategy is redundant, at best.
According to the National Health and Nutrition Examination Survey conducted by the U.S. Centers for Disease Control and Prevention and published in Wednesday’s edition of the Journal of the American Medical Association, the obesity rate among pre-school American children plummeted 43 percent over the past ten years. Only 8 percent of two- to five-year-olds were obese in 2011–12, down from 14 percent in 2003–04.
Such good news is a veritable shock to anti-obesity campaigners, but it should not be. Despite being based upon the deeply flawed Body Mass Index height-weight ratio that inflates the obesity rate, official statistics have shown for some time that the child obesity “epidemic” had leveled off.
For example, an earlier CDC childhood obesity study, also published in the Journal of the American Medical Association, examined the BMI of children between 1999 and 2008, the decade during which childhood obesity was consistently described as America’s preeminent public-health problem.
The results were striking. At no time during the study period was there a statistically significant trend, except for boys at the highest BMI levels. In other words, any spike in obesity was narrowly confined to a very small number of very obese boys.
More recently, the CDC found that childhood obesity rates had fallen in some states (such as New York, Mississippi, and Pennsylvania) during the past few years. Most recently, the CDC documented a decline in the obesity rate among low-income children. Therefore, the very latest CDC data confirms rather than breaks the news that obesity rates are on the decline among American children.
How will the anti-obesity lobby, which describes childhood obesity as an epidemic and advocates using the extensive powers of the state to combat it, respond to such positive, yet professionally awkward, news?
It will arrogantly assert that the decline is due to the raft of regulations and policy interventions it shoved down American throats in recent years. This analysis is as inaccurate as it is self-serving.
Federal, state, and local governments have attempted to tackle obesity by introducing an all-too-familiar menu of policies and regulatory items. The major “solutions” include advertising restrictions and bans, school vending-machine bans, healthier school meals, zoning restrictions, and warning labels.
There are three major problems with these solutions. First, they fail to conform to the standards of evidence-based medicine. There is strikingly little clinical evidence that any of these measures have reduced obesity in children. It is a reasonable requirement that proposed interventions rely upon on rigorous clinical evidence of efficacy. Yet, there is an almost complete absence of even the most flimsy evidence of effectiveness for all of the measures.
Second, they are based on the crucial assumption that obesity is caused in large measure by the environment in which children live. This assumption is contradicted by the accumulating evidence on just how small the environmental contribution to obesity really is.
For example, research suggests that for twins the shared environment effect for both BMI and waist circumference is only 10 percent, which suggests that changing that environment would have an insignificant impact on the prevalence of obesity.
Third, they violate the central canon of evidence-based medicine, in that they are not connected with the cause of the problem. And, because they are not connected with the root cause of the problem, they are doomed both to be beside the point and to be unsuccessful.
Indeed, there is an almost complete lack of high-quality evidence, for instance, about precisely what causes children to become obese. Nonetheless, the solutions typically advanced for childhood obesity confidently assume that we know not only what causes it, but how to prevent it.
It was a fitting irony that Wednesday also saw extensive media coverage of Mrs. Obama’s latest proposal to tackle childhood obesity: a ban on the advertising of junk food and sugary drinks on school property. Going forward, school vending machines (already cleared of the most offensive foods and sodas) and athletic scoreboards would only be able to provide advertising space for government-approved diet drinks and bottled water.
However, the comparatively svelte nature of America’s youngest children has now been definitively documented by the federal government’s own experts. The press release accompanying the CDC study included this schizophrenic quote from Mrs. Obama: “I am thrilled at the progress we’ve made over the last few years in obesity rates among our youngest Americans.”
Yet, the First Lady will continue her misinformed and unnecessary anti-childhood obesity campaign, which was always a solution in search of an actual public-health problem. The new CDC data applies an empirical exclamation mark to that fact.