Thoughts on the “Obesity Epidemic”, BMI, and who determines if we are healthy
I have a guest post for you today.
When I think of the term “obesity epidemic” my skin crawls. It’s an incredibly ominous turn of phrase, one with confusing parameters, based on a system that doesn’t apply to a lot of people (I’m talking BMI here.) Although I have always known that I am skeeved out by the way body mass index is used to shame people, I didn’t exactly have the language to talk about why. Thank goodness for this article, and my friend Josey Ross.
Neoliberalism and Health Part 1: The Obesity Epidemic
by Josey Ross
We’ve all heard about the obesity epidemic. We’ve all seen the footage on 20/20 or the nightly news of large, headless bodies intercut with Big Gulps full of soda and fists full of potato chips. And many of us have felt uncomfortable with the rhetoric used in the “fight against obesity” but maybe haven’t been sure why. Is it the unsettling awareness that those headless bodies belong to real people with real feelings? Is it the use of the word “epidemic” which evokes fears of uncontrollable spread and imminent death? Or is that we ourselves (or perhaps someone we love) have large bodies and yet are healthy—with consistent exercise routines and healthy, nourishing diets, and no indicators of the diseases that are always listed any time the word obesity is uttered.
Maybe it’s a little bit of all of these things. Or maybe it sparks a few questions: who profits from this language? Why do we understand obesity this way? Is obesity necessarily synonymous with poor health?
I wrote, recently, on my blog a series on Neoliberalism and Health—looking specifically at how culture and politics shape our understanding of what health looks like and why the focus on obesity may be misplaced. Lacy kindly asked me to guest-blog here on Super Strength Health and suggested I throw away the jargon (good idea!) and make it a little bit more accessible since academic writing isn’t exactly where most people go to relax after a hard day.
So let’s talk about this “obesity epidemic”. Despite the surety of diet gurus and Dr. Oz, when it comes to the so-called dangers of obesity, the science just doesn’t stack up. Rather, it seems, obesity may be a symptom of a larger set of issues including the hyper-palatable and exceptionally abundant Standard American Diet and the fact that we are, as a culture, way too sedentary for good health.
Any time we hear obesity we are sure to hear these three letters follow: B-M-I. But what is the BMI? The Body Mass Index basically calculates a person’s body fat by dividing weight (in kgs) by the square of height (in metres). Interestingly, the forerunner of the BMI, the Quetelet Index, had nothing to do with obesity or even health. Rather, it was developed by a statistician in the 19th century who was trying to quantify “the normal man”. Flash forward to the mid-20th century and you’ll find an insurance company that noticed a link between mortality and height-weight ratio. In order to maximize the money that the insurance company could make off of its customers it developed a table defining “ideal weights”—basically, the lower your risk of death the less likely it is the insurance company has to pay out a settlement. So they can charge people with a higher risk of death more for a life-insurance plan to maximize their profits. Which, you know, is kind of crappy but also precisely what we expect insurance companies to do. So nothing too shocking here.
But then the National Institutes of Health and the World Health Organization used these “ideal weight” values along with the BMI to calculate obesity and the problems started. So here are the big three issues with BMI: the data collected by the company was almost exclusively from Caucasian individuals but the BMI is used for people of all ethnic backgrounds (what else is new). What this means is obesity rates are overestimated in African Americans and underestimated in people of Asian descent. (There are likely other issues across ethnicities due to variations in bone structure and musculature but these are the two populations that have been studied). Another issue is that the BMI was developed to assess populations not individuals, which makes it somewhere between inappropriate and downright harmful when used at the individual level. Finally, BMI is not able to take into account different body compositions so really tall people, really short people, elderly people, pregnant people, and very muscular people tend to have BMIs that are very inaccurate reflections of their body compositions.
So we know the BMI is a crappy measure of body composition (never mind health itself) but it’s indisputable that North America has a problem with obesity and overweight, right? Well…not quite. See, for much of human history what we today call “overweight” (a BMI of 25-29.9) was considered a sign of good health—after all, you have enough to eat and don’t have any diseases or back-breaking labor that impact your ability to keep a bit of meat on your bones. But you’re right, there was some concern starting in the 1980s in medical and academic settings around the growth of obesity in America. But the idea didn’t really take hold until 2000. This happened for three reasons. The first was the publication of (methodologically flawed) maps tracing the “obesity epidemic” by the Centers for Disease Control. Rather than being simply an issue of statistics, it had become a spreading infection with brightly colored “hot zones”. The second is what has been called “the diseasing of America” which basically refers to the way that the health infrastructure branched out from infectious diseases which were quickly being eradicated or at least well contained into life-style issues in order to justify their continued existence and maintain profits. Perhaps most shocking is the fact that the BMI guidelines for what constitutes “normal weight” changed literally overnight in 1998 from 27 to 25. So several million Americans went to bed “normal” weight and woke up overweight.
So we’ve problematized the BMI and its essentially arbitrary cut-offs, right? But wait! There’s more! See, the narrow-minded focus on the BMI misses all sorts of things, from the fact that my happy weight is probably different from your happy weight even if we’re the same height, to the fact that it misses entirely all the other pieces of the health puzzle including exercise and food behaviors, the impacts of being wealthy or living in poverty, and the fact that access to healthy food and safe spaces is very much related to race and class.
Another issue is that the mountains of literature purporting to link obesity with poor health are, well, not that clear cut. Rather, the evidence that weight loss improves health is contradictory, and the literature used to prop up arguments linking overweight with poor health is full of problems, limitations, and ambiguities. And yet this problematic literature is used to push size-based approaches to health which have profound consequences including eating disorders, stigmatization and mental health issues for those who aren’t able to make themselves “thin”, and an excuse for the powers that be to ignore structural issues (also known as the social determinants of health) in favour of putting the focus on how much I eat and whether I exercise and whether my body fits a narrowly-defined “normal weight range”.
Next time I will look at how health has become a moral imperative, which has made food and exercise into moral issues. If you’re interested in a more in-depth (though admittedly less readable) exploration of these topics I invite you to check out my blog.