An article published in the New England Journal of Medicine predicts the future prevalence of obesity among adults in the United States based on the current prevalence of childhood obesity, and simulation models incorporating prevailing patterns of weight change over time. The news is far from good. As stated succinctly by Reuters among the extensive media coverage, nearly 60% of American children are on track to be obese by age 35.
This ominous figure may fail to impress for seeming too familiar. The combined prevalence of both overweight (a body mass index above 25) and obesity (a body mass index above 30) among adults in the U.S. is often cited as roughly 70%. The prevalence of obesity alone, however, is below 40%- so the newly published projections indicate a rather dire exacerbation of the nation’s obesity epidemic.
The consequences of this would be hard to overstate. Obesity imposes a severe toll on physical and psychological health even during childhood. Those risks only increase over time, and pertain to lesser degrees of overweight as well as obesity.
That latter point, that the risks of obesity apply to overweight as well, is a clarifying update to two prior and somewhat misguided notions. The first was that there is an “obesity paradox,” meaning a health advantage with at least some amount of overweight along with the obvious disadvantages attached to more severe obesity. The more recent and better quality research on this topic, however, indicates this is untrue; there is no obesity paradox. Being overweight throughout adulthood, let alone childhood, increases diverse health risks.
The second contention that proves to be false is that “fitness” can fully compensate for the metabolic risks associated with “fatness.” The reality here, also clarified in the more research and carefully controlled studies, is that fitness and fatness both contribute independently to health status. Leaving aside the fact that few people manage to be both significantly fat and fit simultaneously, the evidence is now clear that at any given level of fitness, excess body fat still imposes metabolic harm.
Some of that harm is now more or less common knowledge. Obesity is the primary driver of the type 2 diabetes epidemic affecting ever more of the modern and modernizing world. As recently as my own medical training, what is now called “type 2” diabetes was called adult-onset diabetes, to distinguish it from the type 1 variety that occurs in early childhood as the result of an auto-immune process. Over the span of my own medical career, I have witnessed the transformation of what was a metabolic disease generally limited to overweight, middle-aged adults into a pediatric scourge. That transition, and the accompanying name change, are attributable all but entirely to changing obesity trends.
Obesity contributes significantly to the risk of heart disease and stroke. There is evidence that overweight and obesity contribute to the risk of dementia, much of which is thought to result from cardiovascular disease, insulin resistance, or both. Perhaps less well known is the contribution of obesity to the risk of nearly every kind of cancer. The role of obesity in many other varieties of chronic misery, from the constant pain of osteoarthritis, to the perennial exhaustion of sleep apnea, is well established.
In short, obesity is intimately involved in the causal pathway to virtually all of the major plagues of modern epidemiology. And the new study indicates that the prevalence of obesity, and consequently of such plagues, will only rise.
This is as much travesty as tragedy, because obesity, of course, is all but entirely preventable. Before we systematically eliminated physical activity from the typical daily routine, and made hyper-processed food continuously ubiquitous, obesity was very much the exception rather than the rule. In places where eating reliably involves real food and physical activity is culturally normal, it still is.
There are public policies, particularly in the realm of behavioral economics that could make a sizable, salutary difference in the rates of chronic disease and obesity alike. But the most obvious of imperatives is to stop propagating obesity for profit.
As long ago as 2006, we had clear information regarding widespread, sophisticated efforts by Big Food to manufacture a food supply that was, for all intents and purposes, willfully addictive. The story, reported in The Chicago Tribune, was an almost literal smoking gun: food industry and tobacco industry scientists were collaborating to study the effects of flavor combinations on brain activity in the service of selling us more of both products.
Somehow, that stunning memo evoked little more than a cultural yawn, something I confess I have never understood. There is seemingly endless fascination in our culture with conspiracy theories, nearly all of which are nonsense. This was an actual conspiracy with massive, universal impact and dire consequences, and no one seemed to care.
We obviously needed, and received, another prod when much the same message about a food supply willfully engineered to propagate overeating for the sake of profit was delivered by Pulitzer Prize winner, Michael Moss. But here we are nearly a half decade since that compelling reminder, which in turn followed the initial revelation by nearly a full decade, and it’s still just business as usual. Rates of obesity and related chronic disease and disability keep rising not because of any mystery we have yet to probe, but because we seem willing to mortgage the future health of our own children for the sake of corporate profits.
The expression we all know is that misery loves company. The entirely unnecessary public health calamity of rampant and rising obesity rates makes we wonder if companies love our profitable misery.
I very much doubt it. Executives and shareholders are people too; they have families too. Companies can’t possibly love the misery engendered by obesity, attendant chronic disease, and resulting premature death. But it hardly matters, because they certainly are willing to profit from it.
David L. Katz, MD, MPH, FACPM, FACP, FACLM, is the Founding Director (1998) of Yale University’s Yale-Griffin Prevention Research Center, and current President of the American College of Lifestyle Medicine. He has published roughly 200 scientific articles and textbook chapters, and 15 books to date, including multiple editions of leading textbooks in both preventive medicine, and nutrition. He has made important contributions in the areas of lifestyle interventions for health promotion; nutrient profiling; behavior modification; holistic care; and evidence-based medicine. David earned his BA degree from Dartmouth College (1984); his MD from the Albert Einstein College of Medicine (1988); and his MPH from the Yale University School of Public Health (1993). He completed sequential residency training in Internal Medicine, and Preventive Medicine/Public Health. He is a two-time diplomate of the American Board of Internal Medicine, and a board-certified specialist in Preventive Medicine/Public Health. He has received two Honorary Doctorates.