the problem with BMI

diving into the topic of why BMI is so problematic and such a poor indicator of health, as well as why many have made the decision to reclaim the word ‘fat’

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If you’re somewhat new to the Intuitive Eating / Health at Every Size® world, one of the things that might be most confusing is the way in which we talk about weight.

Why BMI Is Problematic

If you’re somewhat new to the Intuitive Eating / Health at Every Size® world, one of the things that might be most confusing is the way in which we talk about weight (and why we reject much of the common rhetoric around weight).  So today let’s dive headfirst into that!

The commonly accepted terms used most often to classify weight is by BMI categories: ‘underweight,’ ‘normal weight, ‘overweight’ and “obese.’

The problem is, BMI utilizes just 2 factors to come up with these classifications: your height and your weight.  

If you’ve read any of my nutrition posts, then you know that there are SO MANY other things that impact our health.

BMI is problematic for a number of reasons not the least of which being that is allows us to judge someone’s health status based on a number using factors that may have nothing to do with our health.

But even before we got to that point, the roots of BMI have been troubling.  Developed as a statistical exercise (never meant for clinical use as a medical instrument) in the 1830s by an astronomer named Adolphe Quetelet, it sought to test whether the laws of probability could be applied to humans at the population level.  Not only was it never meant for clinical use as a measure of health, but it was developed using a population of exclusively white, Europeans (therefore differences in body shape/size across all other ethnic groups were unaccounted for).

Despite the way in which it was developed and what it was developed for, insurance companies chose to apply it as a qualification measure for insuring individuals in 1899 stating that ‘from our mortality records the overweights are clearly less desirable than either the normal or the underweights.’ (Flegal et al., 2013).  Important to note here is that  most of the data insurance companies were using was based off wealthy white males (current, more inclusive data shows a very different picture as you’ll see).  Insurance companies then began passing this literature off to doctors and other health professionals, thus beginning the start of fatphobia and weight stigma that still persists in society today.

We’ve discussed that your weight does not necessarily determine your health.  For instance, a thin individual that smokes, uses illicit drugs, never moves their body and eats hardly anything throughout the day is not someone we would ever classify as ‘healthy.’  But because their BMI may be ‘normal’ and they fit the outward appearance of ‘health’ in this culture (i.e. ‘thin’), then they’re often considered such at first glance (or even initially in a medical setting).  

Whereas someone in a larger body that doesn’t smoke or use illicit drugs, is active and appropriately nourished will often be classified as ‘unhealthy’ at first glance (or in a healthcare setting) simply because their weight and height may cause them to fall into the ‘overweight’ or ‘obese’ category and their body doesn’t fit the outward appearance of health we’ve come to accept.

In addition, the use of terms like ‘’underweight,’ ‘normal weight,’ ‘overweight’ and ‘obese’ have their own problems.  The terms ‘underweight’ and ‘overweight’ imply that there’s some magical weight number we should be in order to be healthy (there’s not).  ‘Normal weight” again implies that there’s some specific number that will guarantee us health.  Finally, when you break down the etymology of ‘obesity’ it infers that one has ‘eaten until fat.’

The problem here is that these terms begin to medicalize and pathologize weight beyond a certain (arguably, arbitrary) number which is not only unhelpful, but downright harmful to the individual.

Reclaiming the F Word

Given all of this, there has been a growing movement to take back the word ‘fat.’  Does it make you uncomfortable to describe someone in a larger body or describe yourself as simply ‘a fat person’?  If so, you’re not alone.  I certainly remember feeling that way when I was first introduced to the idea of reclaiming the word ‘fat’ given how demonized fat is in our cultural landscape.  In our society that saying someone is ‘fat’ has become synonymous with an insult.

However, the National Association for the Advancement of Fat Acceptance (NAAFA) argues (rightly so) that fatness is simply a form of body diversity that deserves respect, the same as someone’s skin color, hair color, gender, sexual orientation, etc.

Take a second to process how it makes you feel.  When someone tells you that you look ‘thin’ – do you cringe?  Someone saying “you’re so skinny!” is often seen as a great compliment.  So why, then, do we feel so differently about the word ‘fat’ as a descriptor? 

It’s because our culture has drilled the false narrative into us that ‘fat’ = undesirable, lazy, unhealthy and ‘thin’ = desirable, attractive and healthy.  

There is nothing innately ‘wrong,’ ‘bad’ or ‘unhealthy’ about fatness – it’s simply a different way for a physical body to present.

That said, I understand reclaiming the word ‘fat’ is not for everyone.  For some, that word can still evoke a lot of trauma (particularly if one has endured a lot of weight stigma throughout their life).  Whether you are someone who feels comfortable reclaiming it to describe yourself or not, the point is that there are many other, much more respectful descriptors you can employ outside ‘overweight’ and ‘obese.’

Some of these include:

• Individual living in a larger body
• Heavier individual 
• Higher weight individual

If you are referring to someone directly, you can always ask them what term they prefer to utilize.  Above all, it’s important to be respectful of the terms individuals feel most comfortable with.  This will change person to person – everyone’s journey and preference is different.

References: 

• Bacon, L. & Aphramor, L. (2014). Body Respect: What Conventional Health Books Get Wrong, Leave Out, and Just Plain Fail to Understand About Weight. Dallas, TX. BenBella Books, p. 8-10.
• Harrison, C. (2019). Anti-Diet: Reclaim Your Time, Money, Well-Being and Happiness Through Intuitive Eating.  Great Britain.  Yellow Kite, p. 35
• K.M. Flegal et al., “Association of All-Cause Mortality with Overweight and Obesity Using Standard Body Mass Index Categories: A Systematic Review and Meta-Analysis,” JAMA 209, no. 1 (January 2, 2013): 71-32. [PDF]

disclaimer: the content that I share in this space should be used for informational and educational purposes only. It should not be used as a substitute for medical or mental health advice and does not constitute a client/practitioner relationship.

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