If a research group today conducted a study on a single gender or ethnic group, critics would be quick to point out that its findings couldn’t reasonably be applied to anyone outside of that gender or group. It seems like basic logic, right?
Unfortunately, such is the case with the Body Mass Index (BMI), a weight-to-height ratio used by health care providers, insurance companies and the scientific community.
There is growing criticism for the use of BMI. For example, it doesn’t take body composition (fat versus muscle) into account, and a person’s weight doesn’t correlate directly with their health. However, there’s not much mainstream discussion about its racist roots or the way it furthers the oppression of and discrimination against certain groups.
A growing number of experts believe it’s time to change that.
The BMI is inherently racist and sexist
The racist roots of the BMI go back a long way. Created by Belgian mathematician Adolphe Quetelet in 1832 as the “Quetelet Index,” the scale was created using data from predominantly European men to measure weight in different populations.
Although Quetelet noted that it was a population-level tool and not meant to be used on individuals, physiologist Ancel Keys reintroduced the calculation in 1972 as the Body Mass Index, and it has since been adopted by the medical community as a way to measure individual health. A BMI outside the “normal” range (18.5-25) is considered less healthy, and an indicator of greater health risks.
While the BMI has countless failings as a reliable tool, racism is chief among them, said Sabrina Strings, an assistant professor at the University of California, Irvine.
“It is racist, and also sexist, to use mostly white men within your study population and then try to extrapolate that and create norms and expectations for women and people of color,” Strings told HuffPost. “They have not been included in the initial clinical analyses, and therefore their actual health outcomes cannot be determined by these findings.”
In short, the way BMI is being used is unscientific because of its origins and the homogenous population it was created from.
Weight standards have long been used to perpetuate racism
In her book ”Fearing the Black Body,” Strings outlines the history of body standards and the ways in which thinness was used to uphold white superiority as recently as the early 20th century.
She describes how the thin bodies of northern and western Europeans were upheld as the ideal, while the often larger bodies of eastern and southern Europeans, as well as Africans, were considered signs of their inferiority. All of this was before we really knew anything about the (still blurry and confounding) relationship between weight and health. The modern BMI and its categories ― underweight, normal, overweight and obese ― have inherited much of that racism.
“Even after all of the work that I’ve done and the work that I’ve read about the creation of these weight categories, I’ve long wondered, ‘Who is this even based on?’” Strings said. “This 18.5-25 ‘normal’ BMI category that they arbitrarily came up with ― what is that even about? There’s something so strange about that. I feel almost certain that they were not researching people in places like Samoa, where people can be healthier at much heavier weights.”
“There are so many ramifications of trying to create one normative table for the diverse people of the world,” Strings added. “The whole thing is preposterous.”
Making assumptions about a person’s health based on their BMI is preposterous
Racism aside, BMI just isn’t a very good measure of a person’s overall health.
“At present day, [BMI] has been widely adopted by the medical world as a shorthand for healthy or unhealthy,” said Jennifer Gaudiani, an internal medicine physician and certified eating disorder specialist based in Denver, Colorado. “That fact is unscientific and harmful.”
For one thing, it can blind physicians to a patient’s actual medical conditions. Many males with anorexia nervosa go undiagnosed because they are technically within the “normal” BMI category, Gaudiani said. The same thing happens to people at higher weights, who often don’t get screened for eating disorders despite things like significant recent weight loss, symptoms of malnutrition or reported eating disorder behaviors.
Gaudiani described another instance where a former patient of hers had lymphoma that was written off by her former doctor as “part of her fat neck” until it was stage 4.
While Strings and Gaudiani both pointed out that weight is linked to certain medical conditions, they emphasized that being at a certain weight doesn’t make a person healthy or unhealthy.
The experience of racism can affect BMI
It’s important to note that while the average adult American BMI falls into the “overweight” category, there are marked differences between ethnic groups. According to the Centers for Disease Control and Prevention, the prevalence of “obesity” (a BMI over 30) is highest among Black adults, followed by non-Black Hispanic adults. But it’s discriminatory and unfair to make blanket statements without examining why this is the case.
“The question is, what contributed to higher weight across an entire [ethnic] population? The answer lies in poverty, in minority stress, in experienced traumas related to food inaccessibility and fear and worry in the household about safety or financial security,” Gaudiani said. “It lies in the propulsion of diet culture onto certain groups in ways that start weight cycling from a really early age and do not honor body diversity.”
She explained that a young girl of color might go to a pediatrician at age 7 or 8 and be told that they’re fat, when in fact they’re just experiencing a normal prepubescent weight surge earlier than a young white girl might.
“That sets up in them a body consciousness and fearfulness or maybe even dieting pattern, that may indeed affect metabolism and, later in life, body weight,” Guadiani said.
What’s more, just the experience of racism can affect a person’s weight and BMI.
“I think that racism has a multi-system impact on the body,” said Lesley Williams, a family medicine physician and certified eating disorder specialist based in Phoenix, Arizona. “It’s waking up every day and dealing with micro- and macro-aggressions that you’re maybe not even familiar with but your body is absorbing … It has an impact on stress levels, which can then increase cortisol levels, which then impacts the body’s composition.”
In turn, those at higher BMIs experience even more discrimination.
While discrimination and lack of access to quality medical care can affect BMI, they can also simultaneously be the result of a higher BMI ― an endless cycle.
Williams explained that many doctors believe that when a person is at a higher BMI, it is not only their right but their obligation as a doctor to try and intervene: to encourage the patient to lose weight, discuss the patient’s body size and eating habits without the patient’s permission, and address this “issue” of weight before discussing whatever medical problem the patient may have come in for.
“That’s doing harm, and can negatively impact someone’s mental and physical health,” Williams said.
“I’ve had so many patients who have specifically sought me out in the past because I advertise that it’s a safe environment, who have been avoiding health care because they have felt that it is unsafe,” Williams added. “I hear time and time again, ‘My physician wouldn’t listen to me. I had this myriad of complaints that had nothing to do with my weight, and all they wanted to do was talk about my weight, and I was not being served, and I’ve just elected not to go back.’”
As Gaudiani mentioned, this can lead to legitimate health issues going unchecked and unmonitored, which in itself can greatly worsen health outcomes. Yes, a person’s weight might serve as one data point in their medical profile, but no single number can determine how healthy someone is overall.
“We cannot use weight as a marker of health,” Gaudiani said. “It just does not correlate, except on the very extremes.”
Unfortunately, there’s no easy substitute. Both Gaudiani and Williams agree that the answer isn’t to just replace the BMI with another basic measurement ― say, taking a person’s muscle mass or body fat percentage and using that instead. These too are only single factors, and can’t predict health outcomes.
Instead, Williams thinks that doctors must take all of a person’s health markers into account when determining their health. That includes factors like their background, their stress levels, their access to food and dietary habits, any underlying health concerns or conditions, their relationship with movement and exercise and more.
Of course, this takes more time and doesn’t come out to a single number that can be entered into a chart.
“I think BMI is used because it’s a very blunt tool, if you will, and it’s easy,” she said. Instead of making assumptions based on a patient’s BMI, she focuses on whatever issue brought them to her office, collects the data she needs, and targets her intervention based on those specifics. It might be a little more time-consuming, but it’s also more accurate and patient-centered.
The BMI won’t disappear overnight, nor will racism or discrimination against those at higher weights. But the number of physicians and other experts beginning to reject, or at least seriously question, its validity as a tool for measuring health is growing. While we all work to break down racism and racist systems in America, we must also hold the medical community accountable for their role in perpetuating these systems through the use of flawed tools like BMI.
