The American Medical Association’s decision last month to label obesity as a disease has provoked a good deal of commentary, much of it critical. In fact, the AMA’s action went against the conclusions of its own Council on Science and Public Health, which had considered the issue over the past year.

While no analogy is perfect, in terms of the magnitude of a societal problem, the example of smoking offers a number of points relevant to the discussion of obesity.

Smoking is a personal behavior that waxed dramatically and then waned dramatically over the course of the 20th century. Smoking causes a wide range of diseases from lung and other cancers to cardiovascular disease and chronic respiratory diseases. Over the past century smoking is estimated to have caused 1.6 million deaths in the United States. However, no one ever proposed labeling smoking a disease.

In the 1950s nearly half of Americans smoked. Starting with the publication of the first Surgeon General’s Report on Smoking and Health in 1964 the prevalence of smoking declined from 42 percent to 19 percent in 2010. This occurred in spite of the fact that smoking is a highly addictive behavior. Thus, over the past 50 years, we have witnessed a profound change in society’s attitude toward smoking and this change has been accompanied by a substantial reduction in smoking prevalence.

The decline in smoking prevalence is the result of wide variety of actions, including public education, increased taxes on cigarettes, restrictions on advertising, warning labels on cigarette packs, ordinances and laws affecting smoking in public places, smoking cessation programs, and the consideration of smoking habits in setting health insurance premiums. In addition, importantly, as the proportion of smoking population dwindled, public attitudes have changed, and smoking has become “de-normalized,” not to say stigmatized.

The analogy with obesity is imperfect, first because one can live without smoking but everyone has to eat, and controlling what and how much one eats and how physically active one is in our sedentary society is a real challenge.

Second, in contrast to smoking, the definition of obesity — a body mass index, or weight in kilograms /(height in meters squared) of 30 or above — is a crude metric. An estimated 30 percent of those classified as obese are actually healthy in terms of their cardio-metabolic profile, including such things as circulating glucose, insulin, and cholesterol levels. In this group of “healthy obese,” prescribing weight loss may actually be harmful. Furthermore, in the most detailed analysis of data worldwide carried out to date, having a BMI of 30-<35 kg/m² was not associated with a higher death rate. Only at levels of extreme obesity (35 kg/m² or greater) does one see an increase in the death rate. Those who are overweight (BMI of 25-30) actually have the lowest death rates.

Another aspect of the decline in smoking prevalence that should be borne in mind is that smoking has been reduced predominantly among those with more than a high school education. Thus, smoking has largely become a habit of those with lower socioeconomic status.

While the rates of obesity in men do not vary by SES, among women higher SES is associated with lower levels of obesity. As the many initiatives to reduce obesity develop, it will be important to ensure that they don’t preferentially affect the more educated and the middle class, but are tailored to address the circumstances of lower income groups as well.

Defining obesity as a disease makes little medical sense, since, rather than judging a person’s health based solely on his/her BMI, a physician needs to examine each patient as an individual, take a detailed history, and assess clinical parameters, such as blood insulin, cholesterol, triglycerides, etc. If these are somewhat outside of the desirable bounds, behavior changes may have the desired effect. If the values are more extreme and if behavior changes are less of a realistic option, then drugs can be considered. But the decision needs to be made based on the complete profile of the individual, not on some arbitrary cut-point in a proxy variable.

All of these points argue against classifying obesity as a disease. Above all, however, labeling something as a disease is a way of excluding it from normal, everyday life. But the point is that obesity is totally normal and totally integrated into our way of life.

Furthermore, as has been pointed out, classifying obesity as a disease in a blanket fashion will stigmatize those so labeled and in some cases will add to the sense of lack of control over their health and to an attitude of fatalism.

This is not to ignore the role of individual responsibility, but it is wildly moralistic and unrealistic to assume that growing up in an environment with a super-abundance of calorie-dense foods, jobs that are largely sedentary, and neighborhoods unsuited to physical activity has no effect on the body weight of the population. We tend to over-estimate and idealize what the individual can do by resisting the prevailing current.

Instead of regarding obesity as a disease of the individual – with the resulting medicalization of the problem and the incentive to prescribe drugs that this implies – it makes much more sense to view obesity as a societal problem or, more accurately, as a problem involving the interaction of the individual with what has been called the “obesogenic” society.

In one of the most thoughtful responses to the AMA pronouncement, Dr. David L. Katz, the director of the Yale University Prevention Research Center, gives a compelling description of obesity in its societal context. It’s worth quoting what he had to say:

Our bodies, physiology, and genes are much the same as they ever were. Certainly these have not changed much in the decades over which obesity went from rare to pandemic. What has changed is the environment.

We are awash in highly-processed, hyper-palatable, glow-in-the-dark foods. We are afloat in constant currents of aggressive food marketing. We are deluged with ever more labor-saving technological advances, while opportunities for daily physical activity dry up.

We are drowning in calories. And that’s how, in my opinion, we should make obesity medically legitimate: as a form of drowning, not as a disease.

With drowning, we don’t rely on advances from pharmaceutical companies. No one is expecting a drug to “fix” our capacity to drown. Our capacity to drown is part of the normal physiology of terrestrial species.

Our capacity to get fat is also part of normal physiology. Obesity begins with the accumulation of body fat, and that in turn begins with the conversion of a surplus of daily calories into an energy reserve. That’s exactly what a healthy body is supposed to do with today’s surplus calories: store them against the advent of a rainy (i.e., hungry) day tomorrow. The problem that leads to obesity is that the surplus of calories extends to every day, and tomorrow never comes.

Thinking of obesity as a form of drowning offers valuable analogies for treatment. We don’t wait for people to drown and devote our focus to resuscitation; we do everything we can to prevent drowning in the first place. We put fences around pools, station lifeguards at the beaches, get our kids to swimming lessons at the first opportunity, and keep a close eye on one another. People still do drown, and so we need medical intervention as well. But that is a last resort, far less good than prevention, and applied far less commonly.

There is an exact, corresponding array of approaches to obesity prevention and control; I have spelled them out before.

Disease is when the body malfunctions. Bodies functioning normally asphyxiate when breathing carbon monoxide, drown when under water for too long, and convert surplus daily calories into body fat. Perfectly healthy bodies can get obese. They may not remain healthy when they do so, but that is a tale of effects, not causes.

The most important reasons for rampant obesity are dysfunction not within our individual bodies, but at the level of the body politic. We do need medicine to treat obesity, but more often than not, it is lifestyle medicine. Lifestyle is the best medicine we’ve got — but it is cultural medicine, not clinical.

That’s where our attention and corrective actions should be directed. If calling obesity a disease makes us treat the condition with more respect, and those who have it with more compassion, and if it directs more resources to the provision of skill-power to adults and kids alike, it’s all for the good. But if, as I predict, it causes us to think more about pharmacotherapy and less about opportunities to make better use of our feet and our forks, it will do net harm. If we look more to clinics and less to culture for definitive remedies, it will do net harm. If we fail to consider the power we each have over our own medical destiny, and wait for salvation at the cutting edge of biomedical advance, it will do net harm.

Long before labeling obesity a disease, the AMA lent the full measure of its support to the Hippocratic Oath and medicine’s prime directive: First, do no harm. Obesity is much more like drowning than a disease. Calling it a disease has the potential in my opinion to do harm. And so it is that I vote: No.

If Katz can be faulted for anything, it is that he fails to acknowledge the considerable socioeconomic differences between groups and neighborhoods in terms of environment, “culture,” and resources to combat obesity. The history of decline in smoking prevalence alerts us to the danger that increasingly obesity may become concentrated in lower income groups.

A recent focus by public health specialists on the immediate environment of neighborhoods, including walkability, the availability of parks, safety, and the availability of affordable fresh produce, indicates that obesity is embedded in the fabric of everyday life, and it is unlikely to be affected by simplistic or rhetorical gestures. Rather, what is needed are programs based in schools, communities, and the medical establishment that address modifiable aspects of the environment in order to promote changes in behavior, including better nutrition and greater physical activity. What is needed are fundamental changes in the “built environment” and our relationship to it including to food.

It’s hard to tell people to go out and run in the park in neighborhoods where there is no park nearby and where you have to dodge stray bullets to go to the bodega to buy a quart of milk.

The society-wide obesity problem is much more complex than smoking, and tackling it will require a much more sophisticated and nuanced approach than what worked for smoking. It will not do to demonize the food industry or to stigmatize the obese. A concerted and persistent effort will be required to devise, test, and implement new strategies for affecting behavior, starting at an early age and in different environments, while incorporating insights from all relevant disciplines.

Geoffrey Kabat is an epidemiologist at the Albert Einstein College of Medicine who has studied a wide range of lifestyle and environmental exposures in relation to cancer and other chronic diseases. In addition to his scientific work, he is interested in risk perception and the public understanding of science. He is the author of Hyping Health Risks: Environmental Hazards in Daily Life and the Science of Epidemiology and writes the "Risk-omics" column at Forbes. This article is reprinted with his permission.

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Obesity Is Not a Disease

Sep 19, 2013