BMI Sucks and a Better Alternative Exists: Is a rebrand all it needs?

We all know Body Mass Index (BMI) is old and outdated yet major health organizations such as the WHO and the CDC, continue to use it as the main indicator for obesity. BMI was created by a mathematician, not a medical professional nor was the tool meant to be used as a health indicator. In modern day, it is dangerous to individuals to have inaccurate understandings of where “healthy” lies for them and may push healthy individuals to strive for goals that are a detriment to their health. Many in the medical community understand the inadequacies to BMI yet most never name an alternative. There is one simple test that does seem to show some promise. 

Waist Circumference to Height Ratio AKA The 0.5 Rule

Abdominal fat is oftentimes linked to a higher cardiovascular risk and the height accounts for different physiological differences. The 0.5 Rule or your waist circumference being less than half your height is a better screening tool than BMI. 

Two major studies support this metric. The first is where they took data from 300,000 adults that showed the superiority of Waist Circumference to Height Ratio as a screening tool compared to just waist circumference and BMI. The second is a review of 78 different studies that test the different indicators and their efficacy as predictors for diabetes or heart disease. 

There are two reasons the BMI fails where the 0.5 Rule does not. First, muscle is denser than muscle and can indicate high BMI for folks with high muscle mass percentage. Secondly, in women it is actually normal to have extra stores of fat in their thighs, hips and butt with no increase to health risk. BMI can inaccurately flag healthy women and athletes as obese as it fails to account for where the weight is actually coming from. 

Does this index help the rampant fatphobic nature of the medical community? No. But it more accurately predicts the health risk that an individual may face across ethnicities/ages and genders. And while the hope is that healthcare grows to be more holistic and view health as a whole picture, a better diagnostic tool should be implemented to improve individual’s health outcomes.

Sources

[1] Waist-to-height ratio is a better screening tool than waist circumference and BMI for adult cardiometabolic risk factors: Systematic review and meta-analysis. - Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews - NCBI Bookshelf 

[2] A systematic review of waist-to-height ratio as a screening tool for the prediction of cardiovascular disease and diabetes: 0·5 could be a suitable global boundary value | Nutrition Research Reviews | Cambridge Core 

[3]The really old, racist and non-medical origins of the BMI - ABC News