Controversy: Requiem For BMI?

By BruceBlaus - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=44922550

Look at this paper; abstract reproduced below.  Now, I agree that BMI is a flawed measure.  It always struck me as odd that the BMI cutoffs for normal vs. overweight vs. obese were the same for men and women, considering that the typical man is larger framed and more muscular than the typical woman of the same height, and would therefore weigh more even if of completely healthy body composition. BMI also does not distinguish between the 200 pound athlete with high muscularity and low bodyfat and the 200 pound coach potato who is extremely obese and unhealthy. So, in that sense, I agree with this paper. However, for the typical person at home trying to figure out how their weight fits on the healthy vs. unhealthy spectrum, BMI can be a useful, albeit flawed, measurement, especially if combined with the common sense considerations mentioned above, and also combined with a look in the mirror to ascertain how the weight is distributed.  The typical person is not going to have access to the tools to accurately measure specific body fat percentage; hence the utility of BMI + common sense + visual observation to make judgments about healthy vs. unhealthy weight.

PURPOSE OF REVIEW:Quetelet reported in the nineteenth century that body weight varies across adults with the square of height. Quetelet's index, now known as BMI, is accepted by most health organizations as a first-level measure of body fat and as a screening tool for diagnosing excess adiposity. Modern imaging methods now, however, indicate that BMI has limited predictive value for estimating body fat and lean mass at the individual level. The use of BMI as a measure of body composition in the clinical setting should therefore be challenged.RECENT FINDINGS:Recent studies enrolling cancer and surgical patients reported discrepant outcomes when BMI was used as a body composition surrogate. Sarcopenia, loss of muscle mass and function, which affects the elderly and those with chronic and acute diseases, is not accurately diagnosed with BMI. The distribution of adipose tissue is not characterized by BMI, specific measures of which have greater predictive value for metabolic impairments and clinical outcomes.SUMMARY:BMI, as the traditional tool for assessing malnutrition and obesity, is not appropriate to accurately differentiate between important body weight components and therefore should not be used for making clinically important decisions at the individual patient level.