We've all been there before: stepping on the scale at the doctor's office. On a scale from mildly uncomfortable to absolutely dreadful, we'd rate it as being closer to the latter.
In recent years, the Body Mass Index (BMI) has come under fire as being an outdated assessment of health that takes a one-size-fits-all approach. I've experienced first-hand how toxic this can be—and a quick internet search led me to discover I'm far from alone on that front.
Curious to know more about this metric's origins (hint: it involves white dudes) and its pitfalls, I called on Dr. Chisom Ikeji—a Critical Care Medicine Fellow at the University of Pittsburgh whose 'tips from a doctor' series on TikTok has become a personal favorite—to answer some of my biggest queries.
Our healthcare systems seem to place an outsized level of importance on BMI. How accurate (or inaccurate) is BMI as an indicator of health?
The Body Mass Index (BMI) is, at best, a marginal indicator of health. In general, many people with a very high or low BMI have higher health risks. However, the simplicity of the measurement makes it a poor marker of health when applied, in isolation, to an individual. When we investigate the history behind its creation, this becomes less surprising.
The BMI was initially invented in the 1800s by Adolphe Quetelet, a European mathematician, and then revised in 1972 by Ancel Keys, an American physiologist, using data mainly from adult white men. It was never supposed to be used as a measurement of individual health, but rather for population studies. As the concern for obesity and related health risks increased in Western societies there was a need by medical professionals, insurance companies, the government, and researchers to establish an effective way to measure and define obesity.
BMI correlated well with other poor measurements available at the time and was easy to calculate. Despite the fact that studies did not show that BMI clearly predicted risk of coronary artery disease, it became the tool to use. Since then, BMI has become the gold standard of defining obesity on an individual and population level, even though the percentiles used may not adequately define the risk of underlying medical conditions.
Does BMI help perpetuate diet culture?
BMI is now directly tied to a weight classification which is used as marker of overall health, so one cannot escape it, even if they tried. At a very young age we are introduced to the BMI whether it’s by a medical professional, family member, school, or through our own efforts to learn about our health.
The limitations of the BMI are rarely focused on. Even if you understand to an extent that it may not be the most accurate measure of health, it’s so engrained in our society that one cannot help but take it into account. So, in an attempt to reach an “ideal” body weight, BMI helps dictate what that number should be, perpetuating diet culture.
BMI doesn’t take factors, like muscle mass or ethnicity, into consideration. How is this harmful?
@dr.chizmd BMI is a scam 🥺 #blackdoctors #medicine #health ♬ original sound - Dr. Chisom Ikeji
The BMI fails to recognize weight distribution (bone density, muscle, and fat) and how they impact weight. It also doesn’t take into account the difference in body composition between racial population groups, gender, or age, which can lead to overestimation or underestimation of health risks in specific populations.
Studies show that BMI overestimates obesity in Black people and underestimates in people of Asian descent. Yet health risks associated with obesity are lower in Black people compared to White and Asian populations and Black people tend to have less fat mass. This means if a health care provider only takes into consideration the patent’s BMI, they may be concluding the patient is unhealthy and at high risk for certain conditions and advise weight loss when their risk is no higher than someone in a lower BMI category.
They also may be attributing medical symptoms to weight when in fact further investigations should be done. Also, they may fail to recognize serious health concerns like an eating disorder, for instance, may be missed because the person doesn’t meet the BMI criteria for underweight. It also doesn’t allow for the consideration of how other factors impact health and weight like economic status, access to food, and education.
For people who are bigger-bodied, BMI can have negative connotations of poor health. How does this create potential barriers?
If healthcare providers stop at the BMI measurement and make negative assumptions based on a number without talking to the patient, they are failing to consider the multiple other factors that determine a person’s health. This can lead to people feeling unseen and unheard leading to mistrust, anxiety, stress, and low self-esteem. It also makes it much less likely that the person will be willing to comply with the provider’s recommendations.
For healthcare professionals, weight biases negatively affect the potential for patient-centered care. A patient-centered care approach leads to effective communication and information giving. In some cases, healthcare providers may misdiagnose or limit their investigation based on the conclusion that the patient’s weight is the cause of their symptoms.
Negative interactions with health care professionals can forever impact a person’s approach to their health and trust in the health care system.
How can healthcare professionals take an all-sizes approach to treating people?
Healthcare professionals need to remember that health isn’t based on weight alone. We are not all supposed to be one size. Health is determined by multiple factors and all need to be taken into consideration when approaching a patient of any size.
There are alternative ways to determine a patient’s health risk in relation to body size other than the BMI. Studies have shown abdominal obesity to be a more accurate predictor of obesity-related conditions than BMI alone. Measuring waist circumference in addition to BMI can help providers make more informed conclusions regarding the health risks of their patients.
Note, these views are her own and do not reflect those of her employer.
Sources
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Phelan SM, Burgess DJ, Yeazel MW, Hellerstedt WL, Griffin JM, van Ryn M. Impact of weight bias and stigma on quality of care and outcomes for patients with obesity. Obes Rev. 2015;16(4):319-326. doi:10.1111/obr.12266
Ian Janssen, Peter T Katzmarzyk, Robert Ross, Waist circumference and not body mass index explains obesity-related health risk, The American Journal of Clinical Nutrition, Volume 79, Issue 3, March 2004, Pages 379–384, https://doi.org/10.1093/ajcn/79.3.379