Throughout 2021, Good Housekeeping will be exploring how we think about weight, the way we eat, and how we try to control or change our bodies in our quest to be happier and healthier. While GH also publishes weight loss content and endeavors to do so in a responsible, science-backed way, we think it’s important to present a broad perspective that allows for a fuller understanding of the complex thinking about health and body weight. Our goal here is not to tell you how to think, eat, or live — nor is to to pass judgment on how you choose to nourish your body — but rather to start a conversation about diet culture, its impact, and how we might challenge the messages we are given about what makes us attractive, successful and healthy.
Given how diverse human beings are, it's logical that pushing all individuals to maintain the same body standards would lead to trouble. Yet, the medical community has done just that when it comes to the use of one simple calculation: The body mass index (BMI).
This number — intended to be an estimate of body fat — is calculated by dividing a person's weight (in kilograms) by their height in meters squared. This calculation has been at the center of America’s fight against “the obesity epidemic,” a phenomenon the dangers of which many researchers have questioned. It is true that our BMIs have been gradually ticking up across the population, and this has caused many in the medical community to be concerned about our increased risk of disease.
But just how reliable is the link between higher BMIs and poor health?
Amidst that angst, body fat has come to be feared as one of the greatest threats to society. According to the U.S. Department of Health and Human Services’ Office of Minority Health (OHM), Black women have the highest rates of "obesity" and being “overweight” — at least in the way those terms are currently defined — compared to other groups in the U.S. This supposedly means that they are more "at risk" for high cholesterol, high blood pressure, heart disease and stroke.
But correlation with disease does not always equal causation of disease, and research shows that weight loss isn’t the effective cure-all it’s been made out to be. In fact, chronic dieting can lead to heart attack and stroke. This all calls in to question whether or not blanket weight loss initiatives and deep-seated fears of “excess” fat are helping or harming the well-being of individuals and communities at large. (Hint: They're harming it.)
But besides the fact that the BMI is not a great assessment of a person’s overall health or even body composition, the hardest reality to digest is what fat activists and allied researchers have been writing about for years: That this number, in both its origins and application is racist.
If you read that last sentence and thought, “The BMI is just a number. How can it be racist?” — table that for a moment. Once you understand how the BMI became the standard of health, you’ll realize how it’s been used, whether consciously or unconsciously, to enact biases and discrimination that are harmful to marginalized people.
Where did BMI come from, and why was it created?
Once upon a time, back in the mid-19th century, there lived a Belgian man by the name of Lambert Adolphe Jacques Quetelet who was interested in studying human traits as they related to crime and mortality. He was many things — a mathematician, astrologer, statistician — but he was not a doctor or a health expert of any kind. Still, he was passionate about figuring out what the “average man” (l’homme moyen, in French) looked like, an idea that already hinted that some people were inherently below average and, therefore, inferior to others.
“If the average man were completely determined, we might consider him as the type of perfection,” he wrote in his book A Treatise on Man and the Development of His Faculties. “And everything differing from his proportion or condition, would constitute deformity or disease ... or monstrosity.”
So, he created the Quetelet Index by using a calculation involving a weight-to-height ratio and set out to determine "the ideal."
And guess what? He collected his data primarily from white European men. So the mean of this data might suggest who was the “ideal” white European man, but not the ideal for all men. What's more, Quetelet never intended that this index be used to measure a person’s health or wellness at all.
“Initially it was used to categorize people and look at the distribution of a population,” says Diana Thomas, Ph.D., a professor of mathematics at West Point who’s published research on exercise and obesity. Population averages cannot determine an individual’s health, let alone “perfection” (as if we could ever, or even want to, quantify that).
Yet somehow in the late 20th century, health and life insurance companies adopted the Quetelet Index to replace their own height-weight tables (which were already based on stats drawn from mostly white men and some white women). As author Sabrina Strings, Ph.D., an associate professor of sociology at UC Irvine, documents in her book, Fearing the Black Body: The Racial Origins of Fat Phobia, health insurance companies in the early 1900s linked "excessive" body fat with an increased risk of heart disease (and still do, even though current science says it's not that simple).
This was significant because insurers could use this information to determine a person’s coverage. Insurers could then refuse to cover the “overweight” while many doctors saw these “medico-actuarial tables” as a quick tool to decide who they’d take on as a patient, according to Strings.
In 1972, obesity researcher Ancel Keys, a physiologist who studied diet, claimed he had the answer. Keys and his colleagues did a large study on fatness, looking at predominantly white European and American men (notice a pattern here?) and concluded that the Quetelet Index, or the “body mass index,” as they called it, was superior to previous height and weight tables in measuring the fat on a person’s body. And thus, the QI was rebranded as the BMI we know today.
Let's recap: Around 170 years ago, a white guy in Belgium, who was never interested in health to begin with, came up with a ratio that years later was adopted by health experts to decide whether or not to treat or insure a person — a ratio that insurance companies and doctors still use today. It's the ratio we still use to discriminate against others and harshly judge ourselves. This is the ratio that we are all told to be concerned about because body fat is supposedly killing us.
But this is not the truth.
All the reasons BMI should stand for "Badly Mistaken Idea"
Currently, a “normal” person’s BMI ranges from 18.5 to 24.9. Anyone who is below the cutoff is considered “underweight,” while those above are either “overweight” or “obese.” And some physicians maintain it is a useful, if imperfect tool. That said...
- The current BMI cutoffs are based on the imagined “ideal” Caucasian and do not consider a person’s gender or ethnicity. Unfortunately, these narrow standards have not changed in America and have been applied globally, like in Central Africa where white people are the minority. However some countries have adjusted their cutoffs. For example, China and Japan have defined “overweight” as having a BMI over 24 (0.9 lower than U.S.’s cutoff).
- Higher or lower BMIs might be healthier for different groups of people. A large 2003 study published in The Journal of the American Medical Association (JAMA), for example, has shown that higher BMIs tend to be more optimal for Black people, and that Black women don’t necessarily show a significant rise mortality risk until a BMI of 37. A 2020 study suggests that while a higher BMI correlated to “harmful” fat surrounding the heart of white New Zealanders, it did not apply to those of Maori descent. Dr. Thomas, whose parents are Indian, sees first-hand how the standard cutoffs don’t fit the experiences of her own family. “You go to my house, there’s always somebody who has diabetes, there’s always someone who has high blood pressure, and they don’t look like what Americans consider obese,” she says. “It’s well documented that there’s higher incidences of all metabolic disorders at a lower BMI for South Asians.” (Dr. Thomas has written a report making an argument for separate cutoffs for people of Asian descent.)
- Since many people with higher BMIs are healthy, the BMI can perpetuate weight bias. Some doctors think that merely adjusting the parameters and finding better tools to measure fat does little to correct the myopic weight stigma embedded in medical practices today. In reality, simply saying “obesity is bad” without considering other genetic, social and environmental factors harms more than it heals. Eating disorder physician Maria Monge, M.D., director of Adolescent Medicine at Dell Children’s Medical Center, has discovered that when doctors are hyper-focused on getting rid of fat, they often assume that patients in larger bodies are unwell. “Many of my [larger-bodied] patients have been told that they’re not healthy, but when I checked their labs and vital signs, everything was pristine,” says Dr. Monge. “The only thing that was out of the range considered 'normal' was their BMI.”
- People in larger bodies tend to get less quality care. When fat is centered as the issue, doctors may misdiagnose or under-diagnose symptoms patients are experiencing. Dr. Monge remembers one patient who came to her with a lump on their neck: Their previous doctor suggested that that lump was there because they were overweight and the patient apparently internalized the idea that the doctor wasn’t going to look at her neck because she was fat. Dr. Monge has also found that in her trainings that physicians tend to overlook when people in larger bodies develop anorexia or other dangerously restrictive eating habits.
- Too much focus on weight can encourage harmful eating habits. The common response to fatness is to recommend dieting, under the assumption that losing weight is a healthy goal because it could also prevent the risk of developing, say, a metabolic disorder like diabetes. But in some individuals, dieting can actually promote disordered eating habits and starvation patterns that increase the risk of diabetes, according to Dr. Monge.
- The BMI and weight bias can discourage bigger people from seeking care, leading to worse health outcomes. Too often, patients in larger bodies often feel judged, unseen, misunderstood and not taken seriously, which discourages many from even seeing a doctor in the first place. Some say that this is the reason high BMI correlates with illness.
- Weight stigma causes chronic stress. The inherent bias that’s fueling the “fight against obesity” is proving detrimental. People in larger bodies are discriminated against not only in medicine, but in the workplace, fashion and other spheres. In a 2016 analysis of data collected from more than 21,000 American adults in the National Epidemiologic Survey on Alcohol and Related Conditions, weight stigma has been associated with increased rates of heart disease, stomach ulcers and high cholesterol, independent of BMI. It is clear that our exposure to diet culture and thin privilege has a major impact on our well-being.
- There are better predictors of health status. "One of the greatest predictors of health outcomes is socioeconomic status,” says to Kim Gould, MS, LMFT, a therapist, a Health at Every Size personal trainer, and the owner of Autonomy Movement. “Socioeconomic status tells us whether we can afford health care, have access to medical treatment, nutritious foods, and opportunities to move our bodies. It also determines our quality of sleep and how high our anxiety levels are. If our bodies are in a state of fight or flight and there’s cortisol pumping through our systems long-term, that’s destructive."
Why the BMI is especially discriminatory against Black women
As mentioned earlier, experts from the OMH suggest that Black women are some of the most "at risk" for "obesity related conditions" like diabetes and high cholesterol because they tend to have higher BMIs.
But these health assessments often fail to consider how chronic stress, economic inequality and institutionalized racism affect Black women in America, according to Strings. This painful oversight is rooted deep in our history. In her book she describes how the idea of blaming fatness for Black women’s health problems echoes 19th century pseudo-science that claimed Black women would eventually die off due to their "animal appetites'' and “unwieldy size.”
This sort of thinking clouds over the systemic issues that impact the health of Black women. For example, BIPOC women disproportionately live in food deserts and areas with polluted air and water systems — all of which can contribute to the development of chronic illnesses. Meanwhile, many Black women lack access to quality healthcare and health insurance. This sort of thinking also ingrains an intolerance for racial and physical diversity that curbs our ability to really care for one another.
"So, when we’re talking about health in marginalized communities, we need to find out about the health issues on the ground," says Strings. "We need to understand their context, their histories, and then we need to work with them to improve their health. There is no need for us to have a top-down approach [like BMI categories] that serves to stigmatize. Instead, we can think about ways that we can care for people without making them feel like they have to change who they fundamentally are."
So, what do we do with the BMI?
Since the BMI is very much ingrained in medical practice today, it’s here to stay for the time being. The Center of Disease Control and Prevention (CDC) currently describes the BMI as an “inexpensive and easy tool” to screen for health risks, even though it also plainly states it “does not diagnose the body fatness or health of an individual.”
Thankfully, there are more physicians catching on to the fact that the BMI is not in fact necessary. For example, Health at Every Size (HAES) -informed doctors and other health practitioners who practice fat acceptance tend to examine their patients’ needs through more reliable measures like blood pressure, cholesterol and other biomarkers.
According to Dr. Monge, a patient’s weight oftentimes does not even need to be measured to give quality care, except in very specific cases (like if weight affects a person’s medication). Even then, there are ways that physicians can approach the process as not to shame or trigger their patients who have gone through years of experiencing fatphobia, she says.
If you find your doctor is not the most mindful around these conversations and you’d like to see another physician, you can shop around the HAES directory or the Association for Size and Diversity professional list. But if you’d like to (or need to) stay with your M.D., there’s usually some room to have a discussion about how you’d like to be treated. One thing you can do is ask for blood work (if it hasn’t been ordered already) to ensure your doctor isn’t conflating your weight with your health. You can also ask your doctor to refrain from sharing your weight with you if the number causes you distress.
“Sometimes people have little cards that they take with them to health care visits, and they'll say, 'I prefer not to be weighed. But if you feel like it's necessary for something that you need, please do not share my weight with me,'” says Dr. Monge.
The bottom line: No matter where you land on the weight spectrum, just know that when it comes to your well-being, your weight does not determine your health — and that the BMI has been used for a lot of BS.