BMI: More like BM-why is this still a thing?
BMI, or body mass index, was created in 1830 by mathematician Adolphe Quedelet for the purpose of measuring the degree of obesity across a population, not the individual person. BMI does not consider age, sex, race, or body composition. It wasn’t until 2023 that the American Medical Association (AMA) adopted a new policy: “Due to significant limitations associated with the widespread use of BMI in clinical settings, the AMA suggests that it be used in conjunction with other valid measures of risk such as, but not limited to, measurements of visceral fat, body adiposity index, body composition, relative fat mass, waist circumference and genetic/metabolic factors.” <<fact check>>
While AMA’s suggestion is appreciated, how is it being applied? How are these other measurements being calculated in clinical settings? I don’t see anyone jumping into hydrostatic weighing pools or prescribing DEXA scans to measure body composition. Of course, I could be wrong as I do not claim to know what every physician in America is doing. That would be ridiculous. However, what I do see are rogue commercial products utilizing BMI to make miscalculations and mess with everyone’s head. From ‘smart scales’ at home, to InBody machines in gyms and Med Spas, and my most recent nemesis: body scanners. I had an eye-opening experience with Fit3D, a body scanning device that claims to calculate many a splendid wellness metrics slathered in snake oil. The first piece of information required of a Fit3D body scan was my height and weight, which was a red flag as those are measurements required for a BMI calculation. On the same day of my Fit3D scan, I also performed both active and resting metabolic assessments, as well as a DEXA scan to calculate percent error.*
Fit3D underestimated my basal metabolic rate (BMR) by >500kCal, miscalculated my fat mass by 4.5lbs, and overestimated my percent body fat by 4%. Translation: the scale actually lied. This 10 second body scan also provided me with a body shape “rating” against an unknown/undisclosed population sample, which is just wrong. Did we learn nothing from Zuckerberg’s rating system for females in the Social Network? That said, I must give credit where credit is due regarding circumference measurements. I believe the Fit3D body scanner gave precise circumference measurements. Due to human error and general variability between measurements, this is something lacking in the fitness industry and likely clinical settings.
Getting back on topic, why are we still using BMI? American Medical Association established that BMI is an imperfect and misleading math equation with historical harm. They declared that more tools need to be used clinically to measure health, but my assumption is that health insurance companies aren’t opening their wallets for alternative measurements to become part of health and wellness visits. (I think I just answered my own question.) Health insurance companies, Med Spas, and vulture circling gadget companies aren’t in the business of providing a weight-loss solution without profit, if at all.
The concept of profit brings to mind Ozempic, and other semaglutide weight-loss injections that are trending. Was the new BMI policy made to open the door for the accessibility of weight-loss drugs to a broader population? Or was BMI deemed unfit as the exclusive qualifier for determining obesity status for the purpose of finding a less discriminatory metric to calculate individual health? The timing is suspect.
*DEXA scans are currently the most accurate body composition tool, according to kinesiology and nutrition professors at UNLV in 2024.