Intention vs. Reality: Why BMI Is Not Just a Tool
The new year is upon us. Last night, many people drank to excess, placed too much significance on where their lips were as the clock struck midnight, and woke up with their heads feeling like some epic battlefield of yore. Some of those same people, along with countless others, are at this moment shaking off the hangover and proceeding to attempt weight loss under such euphemisms as “getting healthy,” “getting fit,” “eating right,” or “taking better care of myself” (and overcrowding my gym for a month or so before they give up and go away until next year).
Yesterday, a piece was published on CSI’s page that addressed the concerns some have regarding BMI. While there are many issues with the way in which the piece addresses anti-BMI arguments, what stood out to me were some assertions about BMI and its uses that rang entirely false: namely, the notion that BMI is just a tool and is never used in unscientific, reductive ways by the medical community and world population at large.
The issue at hand is that BMI is not the simple calculating tool that some scientists and doctors think it is. BMI is often used as a weapon by which to shame, judge, and oversimplify people’s health and wellness.
suggesting that the measure [BMI] is a “demoralizing standard by which to judge a woman’s health” is bizarre: The BMI is not a “standard [of] health” (for men or women); it is a measure of adiposity (fatness). Though there is a strong positive correlation between excess weight and poor health, it is quite possible to be overweight (or even obese) and healthy. Thus the suggestion that the BMI is a measure of health is patently false.
The suggestion that BMI isn’t used to judge women’s (and men’s) health is what’s bizarre. Some health insurance companies charge people with higher BMIs more regardless of any other factors. A hospital in Texas precluded people from being hired based on BMI and no other measure of health, as does Weight Watchers. This is based on the belief that BMI is a sound single measure of health, one that clearly exists regardless of its falseness.
To use myself as an example, my health insurance is through Kaiser Permanente. Every time I go to the doctor, I’m “diagnosed” anew with obesity based on my BMI, as the printout I am handed at the end of my visit plainly states. This is true regardless of why I actually am making the doctor’s appointment in question.
It doesn’t matter if I’ve lost weight (I actually lost 10 lbs. between the visits documented above), begun eating better or exercising more, showed better numbers in terms of my pulse or blood pressure, or otherwise been told by my doctor that I’m doing well and should continue to do as I am: I am “diagnosed” with obesity every. single. time. and instructed to eat better and exercise more, even if I already had been. As per KP’s system, my health is very clearly being reduced to my BMI in relation to the BMI chart standards, no exceptions or circumstances considered.
Many of the BMI critics’ complaints are straw man arguments stemming from a fundamental misunderstanding of what the BMI is and what it claims to do. It is not a tool used by the patriarchic medical establishment for oppressing women, nor pressuring them to conform to impossible standards of beauty. It is instead a generally useful, accurate guide to helping average men and women determine their weight status
The misunderstanding here is not on the part of critics of BMI, but in those who defend BMI on the grounds that it is merely a guide or a tool. Most people understand that shaming others based merely on perceived fatness is a weak argument and so turn to BMI to gild their shaming with science. Check the comments on any article or picture involving a woman who doesn’t conform to the beauty norms of society: show a little tummy or arm fat (i.e. a lack of Photoshop) and suddenly, the entire world is convinced that your BMI is too high and you’re going to die of teh fatness because science. When body-shamers know that they can cite BMI as a medical fact, they can pretend that their offense at someone’s “rolls” or “jiggling” has nothing to do with aesthetic preference and/or social conditioning regarding attractiveness.
Laypeople judging perfect strangers online aside, my doctors in the past have been very good about reminding me that my BMI is too high in a way that was counterproductive. As a chubby teen highly aware of the fact that she was not at all thin, I had a doctor (whom I later fired when I realized that I could do so) who compared her weight and BMI to mine in her efforts to remind me that I was fat. In other words, a medical doctor used BMI to shame me — something that, ironically enough, fed the very depression that whetted my appetite for comforting sugar, fat, and salt.
To be clear, a doctor telling a patient that she ought to eat more fruits and vegetables and to exercise more is not body-shaming in and of itself. Indeed, if we were to glance at the statistics in terms of the average American’s diet and fitness levels, we could easily conclude that most doctors should be making such recommendations to most of their patients regardless of BMI. On the other hand, a doctor saying, “Look at me, I’m 45 and have had two children yet my BMI is just 25. You’re young; there’s no reason for your BMI to be so high” is certainly shaming; replace “low BMI” and “high BMI” with “skinny” and “fat” and it’s clear what is being said here.
It isn’t the fault of the tool itself that it used so crudely and wrongly, of course, but denying that such uses occur helps to bring no one around to its value, let alone encourage anyone to adopt healthier habits — and isn’t that the goal here? If tools are to be judged only on the intentions of their creators and/or their strict definitions, then the guillotine’s bloody reputation is unfair (it was only intended to kill real criminals and in a more humane way than by hanging), the Hitachi is a back-massager being cruelly misused by perverts worldwide, and Lifehacker, that well-known abuser of binder clips, shouldn’t exist.
Even as a simple tool, BMI isn’t cut-and-dried, set-in-stone medical science, especially with regards to assessing the health of a single person. As Dr. Steven Novella says in a comment on the very piece quoted in Bashing the BMI:
BMI is useful in the aggregate, but not applied to individuals, where other factors need to be considered, and other measures are far more accurate. […] We need more data to sort this out.
The discussion about and research into BMI and for what it is and isn’t useful, then, is far from over.
To deny that BMI is used in the way that it actually is in society is to ignore reality in favor of a hypothetical universe where nothing signifies anything other than what is in its stated definition. There is such a thing as connotation above and beyond denotation. In a culture where thinness is considered the epitome of beauty, health, and even moral character, where discrimination is rampant against the not-thin (especially women), BMI cannot so handily be divorced from its actual uses.