Preventive Medicine Column

Dr. David L. Katz

You likely know –from innumerable sources, my rants among them- that obesity is epidemic among children and adults alike, and counts among the most urgent of public health threats in the modern world.  While the U.S. remains the epicenter of this slow-motion disaster, its scope and toll are increasingly global.

You may also be aware that among the many consequences of obesity that collectively threaten not only years of life, but the life in those years, is prejudice.  Bias against obesity runs both wide and deep.  However short the list of socially acceptable prejudice has become in an increasingly “PC” world, obesity seems still to be on it.

To my knowledge, no group is more committed to shining a light on this shameful issue, and letting that light work its disinfectant effects, than my colleagues at Yale’s Rudd Center for Food Policy & Obesity.  Among them, Dr. Rebecca Puhl has emerged as a leading voice on this topic.  Dr. Puhl’s most recent paper, hot off the presses, highlights routinely biased portrayals of obese individuals in photographic images shown on news Web sites.

Before moving on, I want to emphasize that obesity bias is, indeed, shameful.  We don’t blame victims of asthma for their asthma- we look for a cause in the interaction of genetic vulnerability and environmental factors, and focus on treatment.  So, too, for heart disease, diabetes, cancer, and meningitis.  By attacking the victims of epidemic obesity, we single it out from other threats to health for no justifiable reason, compound its harms, and divert resources from attacking its causes.

But now back to my main theme.  Obesity bias is, indeed, rampant, and well documented.  But in all of the literature on the topic that I have seen, one important element gets scant attention.  Seldom does anyone ask: why?  Why are we prone to bias against obesity in the first place?

The knee-jerk response might be that we don’t like how obesity looks- on ourselves, or others.  But that is not an answer, it just reframes the question: why don’t we look how obesity looks?  To some extent, what we do and don’t find attractive is a matter of personal taste.  To some extent, a matter of cultural taste- or fashion, if you will- which changes across both place and time.  But the strong feelings about obesity seem to be quite different in kind as well as degree from feelings about plainness or homeliness in general.  Something very fundamental seems to be in play.

Maybe that fundamental thing is survival.  Maybe the origins of obesity bias run right past culture, to the bedrock of biology.  I’ll try to make the case.

Consider, for purposes of illustration, the persistent lure of fast food, junk food, energy-dense food, oversized portions, and all-you-can-eat buffets in an age of epidemic obesity.  In some ways, this makes as much sense as a drowning person demanding a bucket of sea water.  Why continue to crave what we already have in excess?  At a cultural or attitudinal level, this seems sheer madness.

But we’re not all crazy; we’re just conditioned.  Throughout most of human history, calories were relatively scarce and hard to get (and physical activity was unavoidable).  Calories per unit of currency spent- whether that unit was time, work, sweat, blood, or dollars- was a valid measure of food value.  This is why more food is widely, if not universally, embraced as “better.”  This is why food and currency are, in fact, equated, as in “earning dough,” “being the bread winner,” and/or “bringing home the bacon.”

But we have devised a modern world in which physical activity is scarce and hard to get, and calories are all but unavoidable.  Oversized portions and all-you-can buffets no longer give us anything we need at low cost- they offer us a chance to get fat and sick at no extra charge (and invite many of us to spend a fortune trying to lose the weight we gained for free).  As a measure of value, calories-per-dollar is, to any rational assessment, obsolete.  It has, in fact, become both silly and harmful.

A very similar case might be made for obesity bias.  In the world the way it has always been until quite recently, calories were a rate-limiting commodity in the struggle to survive.  The more any one of us acquired, the fewer would be available to the rest of us- like the grass in Garret Hardin’s famous “tragedy of the commons.” Calories are the quintessential “commons” in the long expanse of human subsistence.

In a clan struggling for sustenance, think about what obesity would represent: the inequitable distribution of calories.  One person getting more than their share- and thus, potentially leaving less for the others.  The rest of the clan would look on and see in obesity…a threat to their survival.  This hypothesis would also account for those 16th century paintings by Rubens and others, in which some extra flesh was clearly admired, desired, and perhaps envied.

Maybe what we think is a conscious attitude about obesity is, in fact, a survival impulse wired into our DNA.  Does anyone want to subjugate their judgment to that of selfish, and in this case, misguided genes?

Why bother to ask ‘why’?  Because knowing why something is broken, rather than merely that it is, might help us fix it.  I believe this is one of those times knowledge can be power.  If we know why we tend to be biased, perhaps we are better empowered to stop.  We should not be ruled by the thoughtless drives of biology, by anachronisms of survival- when we can rise above them to nurture the better angels of our nature.

You need not be lazy to under-exercise and gain weight in the modern world; you simply need to live in the modern world.  You need not be gluttonous to overeat and gain weight in the modern world; you simply need to live in the modern world.

There are- for most of us- plenty of calories to go around.  Obesity now threatens the health not of those looking on, but of those affected.  Bias against it is not just wrong; it is outdated, and silly.  More understanding of overweight is overdue- as is a dedicated societal attack on the problem, rather than its victims.





Dr. David L. Katz;