Body of Lies: Debunking the BMI


By Ashley-Michelle Papon

It’s that time of year again: swimming pools are opening, students are jogging, and if you’re a mom, you’re probably getting fat. According to a new study released in Pediatrics, the official journal of the American Academy of Pediatrics, young mothers are more likely to make poor dietary decisions, less likely to exercise, and have a higher Body Mass Index, most commonly known as the BMI.

The United States has a firm history of economically punishing teenage mothers by denying them access to better resources including healthier food. Still, the most troubling pretext of the article has little to do with the gender disparity or economics skewed to keep the poor poor, but the implication that the BMI of young mothers is an indication of just how unhealthy they are.

Though the BMI has long been touted by medical and athletic communities as the greatest tool of measurement to determine someone’s health, stricter academic scrutiny and authentic scientific study is finding that the BMI as a gauge of health is flawed. Contrary to what you have probably heard several times over, the BMI is not an accurate indicator of how “overweight” you are. And it’s certainly not a viable indicator of your health.

In July of 2009, Keith Devlin of the National Public Radio shared with the world 10 reasons why the BMI is bogus. Urging listeners and readers to take the BMI—and their next meal—with a grain of salt, he patiently explained that, at its core, the BMI was a nonsensical, physiologically inaccurate formula created by mathematician Lambert Adolphe Jacques Quetelet in the early 19th century. Quetelet’s method to create a measurement was calculated by dividing one’s weight in kilograms by the square of their height in meters.

Although it may seem scientifically sound at first blush, the methodology creates no distinction between the weight of muscle versus the weight of fat, despite the fact that fat takes up roughly four times the space of muscle. In other words, there can be quite a difference in your weight and size based on your body type. By failing to evaluate the two body features separately, the BMI delivers faulty results that make being classified as overweight a virtual certainty. And though BMI has some level of success with whole groups of people, its use to determine how healthy one adult can be is questionable at best.

But the biggest weakness with BMI would have to be how it attempts to lock people into rigidly defined categories for underweight, ideal, overweight, and obese. The scale, ranging from 1 to 100, becomes overweight at 25 and obese at 30; it is transfixed in such a way to suggest that when individuals reach 25 or above, they’ve crossed into the territory of being unhealthy. This conclusion begs the question of what unhealthy actually looks like. By relying solely on the BMI for the numeric answer to this question, the aesthetics often don’t bear out to compliment the BMI’s ranking.

And although people think they can eye it the way they can parallel parking, a true visual assessment of one’s physique isn’t something that can be winged. In one of her earliest criticisms of the BMI, blogger Kate Harding launched a photo project showcasing woman with their height, weight, BMI, and a commentary about the accuracy of the BMI’s rating. One volunteer, Laurie, 5’0 and 130 pounds, carries a BMI of 25.4 percent. According to the BMI, Laurie is “overweight,” despite being a size 4. For emphasis, Harding showcases several curvier women, warning viewers not to get too attached because the BMI’s validation that they’re unhealthy suggests they will drop dead of heart attacks and diabetes soon.

Harding’s point was drastic, but the photographs of everyday women unable to meet these unrealistic body standards hammer home the damage done by the promotion of outdated rubrics employed to shame our bodies. What was pioneered in the interest of helping advance medicine has become a modern tool of extremely organized bio-power. The cultural and social obsession with weight management for women has always gone hand-in-hand with the desire to render them less powerful. In a very real sense, the physical reduction of their size is a stripping down of their agency. Since Kevin Smith gave up directing movies and became a factivist following his ejection from a Southwest flight for being “too fat,” this schism has widened to keep persons of size from inheriting power, often out of concern for their health.

Except that that brings us back, full circle, to why the BMI is completely bogus. The BMI is billed in a way that if someone has a BMI that places them in the “overweight” range, they are immediately considered unhealthy. Yet new research is finding that heavier people actually have more protection against a number of illnesses and chronic conditions, from kidney failure to infectious diseases and lung issues.

Despite this, it’s not going to stop the diet industry from using the BMI to keep pushing their products. Social attitudes notwithstanding, sources like the International Obesity Task Force and the American Obesity Association are treated as completely legitimate entities when they use the BMI to explain how we, as a society, are doomed because of our size. Despite authoring the majority of the World Health Organization’s obesity reports, both organizations are primarily funded by pharmaceutical and weight loss companies. Is it any wonder that these folks (and others associated with them) have been aggressively campaigning to have obesity classified as a disease? As Paul McAleer over at BigFatFacts concludes, “The ‘obesity epidemic’ is worth billions to the pharmaceutical, diet, weight loss, media, and government agencies fueling it.”

This should leave every person asking themselves: do I want to keep banking my health on a tool designed to tell me my body is flawed so that the companies employing that tool can continue creating a billion-dollar industry?

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  3. […] Body of Lies: Debunking the BMI Filed Under: Media Bias, Race, Ethnicity and Culture Tagged With: Ethnicity and Culture, fat, Fat Prejudice, gendered disparity, men, prejudice, Race, Ethnicity and Culture, Size & Weight, size discrimination, sizeism, wage disparity, wage gap, Women […]