The BMI isn't helpful
Written by Rebecca Mendelson & Grace Lautman
Note: In this blog words such as “overweight” and “obese” may be mentioned purely because of their association with BMI. These are not words we find useful or accurate in our practice!
BMI alone will never determine your health or worth.
Our clients often arrive with wounds from years of dieting and weight cycling originating after that one moment when someone in an authority role stated… “your BMI has gotten too high.” We have seen many people harmed by the idea that their weight or achieving a “normal” BMI would finally bring them the life and worth they want. We have watched individuals navigate fertility treatment searching for the only clinic that takes their BMI, and we have heard countless tales of someone finally feeling more well (yes, physically and mentally), after they finally stopped trying to get their BMI into “normal” range.
This post breaks down where the BMI came from, and some “how to’s” for navigating life without the BMI and weight at the center.
Our other related resources include:
Online Course: Health at Every Size Explained
Blog: Body Positivity vs Fat Acceptance
Blog: Can you practice body positivity and want to lose weight at the same time?
What is the BMI?
The Body Mass Index, or BMI is the (spoiler alert: inaccurate) measurement of an individual's body fat based on two factors: weight and height. Medical professionals have used this tool (which they did not create) to gauge one's health level, categorizing individuals into four primary groups: underweight, healthy, overweight, and obese. Although BMI does not directly measure body fat or say really anything about a person’s health, it has been correlated with various metabolic and health outcomes which is why it’s still in the mix for many practitioners.
Studies (many of them well funded by the diet industry) have correlated BMI with different health outcomes, and have not adjusted for variables like weight stigma, disordered eating, or long term outcomes. Due to the simplicity of its nature, medical professionals and researchers use BMI as an indicator to screen or correlate with different health outcomes. But, correlation does not equal causation.
Where did the BMI come from?
The BMI was created back in 1830 when Belgian mathematician Adolphe Quetelet created an overly simple formula to help him measure and understand the distribution of body weights in a population. Although designed for his population statistic studies, near the mid-20th century Quetelet's formula began to gain popularity and make its way into the medical profession.
His formula was never intended to serve as a health measure (he said this himself)--yet the BMI was starting to be used exactly for that despite its racial and sexist biases. It is important to understand that this formula had been established from studies done only on individuals from European and Caucasian backgrounds. Simply using one equation to screen for health when different populations experience different fat to muscle or bone proportions is not great grounds for generalizing. Forming this calculation under one standard sub-population has led to generalized thresholds that are not universally applicable.
In addition to the BMI’s innate racial bias, we also see a complete sexist background. The original formula Quetelet established (which is still used today) does not differentiate between men and women. In a grand generalization, women tend to have a higher body fat percentage than men, and thus using the same tool to assess the health of both sexes creates great misclassification and health risks framed toward women, classifying them into inappropriate BMI and health risk categories. This overly simplistic measurement tool the medical system uses is based on both racist and sexist backgrounds which should be seriously re-considered.
Why is BMI flawed?
At a fundamental level, as explained above, the BMI is incredibly flawed due to its racial and sexist biases and its inability to reflect one's health status with a simple weight divided by height formula. Categorizing individuals into four main classifications creates an incredibly unrealistic and simplistic view of body size and weight and contributes to weight stigma, which has been shown to be harmful and keep a person from even going to the doctor.
Society has unfortunately associated thinness with being “good” and “healthy” while living in a larger body is “bad” or “unhealthy.” The categories in which BMI place a person carry immense psychological effects, as society has attached a stigma to those labeled as overweight or obese–and people carry those stigma’s around with them. With the BMI principle being based on Eurocentric background, many individuals are then wrongfully labeled into such categories and subsequently do not receive the health care they deserve: care that is not so quickly dismissed through weight-related explanation.
By focusing on weight, health professionals are actually harming their patients. Those classified as overweight or obese frequently neglect visits to their healthcare provider as a way to avoid fat-shaming or just to hear “lose weight” after simply wanting a referral for a physical therapist. In turn, their true health issues go unaddressed, and they do not receive the necessary care. One research paper explains it best: The “conflation of obesity with racialized and colonized communities is part of a long tradition of marking marginalized populations as diseased” and the utilization of BMI continues to perpetuate this idea.
Moving past the weight stigma and oppression that BMI carries, it is also an incredibly flawed health indicator at its base. With only two things considered, height and weight, BMI fails to capture what truly defines a person's health. For starters, it does not distinguish between weight from muscle and weight from fat. A strong example we often see comes from an athlete. Athletes are typically metabolically “healthy” but their high muscle mass would lead the BMI scale to label them as “overweight” or “obese.” Simply using height and weight in the calculation of BMI completely neglects factors such as bone density, fat distribution, age, and lifestyle. The list goes on—BMI is a flawed health indicator on many fundamental levels. It is critical to consider all of this information when assessing one's health.
What if my doctor says my BMI is too high?
If your doctor is saying your BMI is too high, you can advocate for yourself, create a more helpful conversation, or look for a doctor who can work with your boundaries. In an ever-changing world, we would hope that the medical profession would educate their doctors about the harmful effects of BMI and caution against its use. Although we have seen some improvement in this regard (ASDAH is one organization at work here), many doctors are not progressing in this area at all. If it feels bad to go to the doctor, get a new doctor.
If your doctor claims your BMI is “too high,” remember that BMI doesn’t determine your health or worth. It never will. Try some of these suggestions:
Tell your doctor:
“I am not feeling supported by discussions about my BMI– what can I do about (xyz health concern) that doesn’t involve the suggestion to lose weight or diet?” (option to share research that most weight loss results in weight regain after 2 years, and you’d like to avoid weight cycling)
“Let’s say my BMI were “normal” but I still had this ____ health issue– what would you suggest then?”
“I’m not finding this care supportive. This will be my last appointment.”
“I’m certain that you don’t understand my history with dieting, weight, an eating disorder etc– the focus on BMI and the suggestion to lose weight are harmful/unhelpful for me. Where do we go from here?”
Ground yourself in other important aspects of your life and health:
"How am I managing my stress levels or mental health?"
"What is my social support like?"
“How do I feel about my relationship with food or movement?”
“Are there systemic factors like experiences of oppression or poverty or access to health care that are primarily impacting my health?
Mantras:
My health is not moral.
My weight to height ratio says nothing about me or my needs.
It’s my decision how to care for myself.
I deserve respectful care.
This health care provider does not get to define anything about me.
If you find your doctor is not hearing you or changing their approach, look toward a new practitioner through this HAES listing.
Note: It is completely understandable, however, that not everyone can easily or readily switch providers. As a quick note, if your current doctor is not HAES-aligned or informed, know that you have every right to refuse weight checks at the doctor’s office regardless of your size. This will be the first step in moving the conversation away from weight-related disease discussion to a more holistic and comprehensive health assessment.
What is a HAES doctor and how will they assess my health?
With so much discourse around BMI and obesity in the medical profession, it is important to feel that you are being heard and properly cared for. A HAES doctor is someone who centers their care away from weight as the most important part of the conversation. They incorporate a weight-neutral perspective to end weight discrimination and the bias that the typical medical model has created. A HAES doctor will emphasize the idea that one can be healthy regardless of body shape or size, and they try to create an environment where your health stays separate from your worth.
Unlike the typical markers used in conventional healthcare, a HAES practitioner will take a different approach, one that is more big-picture or holistic. Instead of focusing on weight or BMI, they’ll look at how you feel overall, considering lab work, factors such as your energy levels, sleep patterns, and stress levels. A HAES provider understands that weight loss is not a helpful prescription, and so they are looking at root causes as well as other ways to manage your health without focusing on weight and dieting. They ensure that we begin to move away from weight-centered care as they understand weight is not indicative of health or worth and there’s an acknowledgement of the harms of weight stigma.
How to talk about BMI with family, friends, or partners
Navigating conversations about BMI and weight can be extremely difficult and uncomfortable even with the people you feel closest to: family, friends, or partners. It’s helpful to feel you can speak up for yourself if you find yourself in a moment or situation where it feels important to you to do so. As always, if you do decide to say something, know that you might not get a comfy response, and others may not have the education or information you do. Providing context as to why you think a certain way about a subject will always be helpful. Here are some examples:
“I have some different thoughts on size and health.”
“I just don’t find BMI helpful.”
“Because of the ways I’ve felt harmed by the use of BMI and discussions about my body, I will have to exit the conversation if it’s becoming about that.”
“I’m not the best person to talk about weight loss or BMI with since I don’t really subscribe to those ideas anymore.”
It makes total sense to feel confused, torn, or even unsure while navigating the dissonance and mixed messaging we receive through society. One side is pushing the medical model emphasizing weight loss, dieting, appearance ideals, and thinness while the other promotes the HAES model, intuitive eating, and anti-diet. It's a lot of information coming from everywhere, with everyone having something different to say about it, and that is overwhelming!
By continuing to educate yourself and being open to new perspectives, you take the first step in navigating the complex discourse around health and weight. Surround yourself with supportive communities that align with your values. Understand that it can be challenging, but having open conversations allows everyone to grow. Prioritizing overall health rather than weight and setting boundaries is a great way to ensure you are in more supportive environments. So yes, although navigating the mixed messages we receive in society can be tricky, there are many ways to feel more comfortable in your approach; and of course, always honor what feels right to you first.
Amazing resources and websites to look toward:
Health at Every Size® Healthcare Provider Listing: Find Healthcare providers aligned with the HAES principle.
The Health Sheet Library: Learn about different health issues and how fatphobia and weight discrimination play a role in treatment.
14 Reasons Doctors Should Not Prescribe Weight Loss: Learn more reasons as to why prescribing weight loss is detrimental.
Why I No Longer Prescribe Weight Loss: Discover a doctor's perspective on why and how they moved away from weight-centered health assessment.
Some great podcasts that surround BMI and HAES
The Appetite
https://open.spotify.com/episode/2kNQHcuZwMcaoHW5OfcZSm?si=3c829d3946eb4128
https://open.spotify.com/episode/5Gm4Ynqrd4c3DKWSvFQtD5?si=196beb1c640f4582
Food Psych Podcast with Christy Harrison)
What The Actual Fork Podcast
Sources:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8443289/pdf/193e1398.pdf
https://www.cdc.gov/healthyweight/assessing/bmi/adult_bmi/index.html#Athlete
https://thischangedmypractice.com/why-i-no-longer-prescribe-weight-loss/
https://minksmedicalnutritiontherapy.com/weight-not-the-best-indicator-of-health/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3041737/pdf/1475-2891-10-9.pdf
https://www.nourishingny.com/blog/haes-provider
