I F*#@’!& Hate the BMI Formula


I hate the BMI formula. I bet you didn’t know it but a man named Adolphe invented the formula back in the 1800’s. Yes a guy named Adolph(e). The formula has been skewed over the years to tell people they’re fat when they are skinny, and skinny when they are fat.

From the World Health Organization (WHO):

Classification BMI(kg/m2)
Principal cut-off points Additional cut-off points
Underweight <18.50 <18.50
     Severe thinness <16.00 <16.00
     Moderate thinness 16.00 – 16.99 16.00 – 16.99
     Mild thinness 17.00 – 18.49 17.00 – 18.49
Normal range 18.50 – 24.99 18.50 – 22.99
23.00 – 24.99
Overweight ≥25.00 ≥25.00
     Pre-obese 25.00 – 29.99 25.00 – 27.49
27.50 – 29.99
     Obese ≥30.00 ≥30.00
          Obese class I 30.00 – 34.99 30.00 – 32.49
32.50 – 34.99
          Obese class II 35.00 – 39.99 35.00 – 37.49
37.50 – 39.99
          Obese class III ≥40.00 ≥40.00

WHO states: “BMI values are age-independent and the same for both sexes. However, BMI may not correspond to the same degree of fatness in different populations due, in part, to different body proportions. The health risks associated with increasing BMI are continuous and the interpretation of BMI gradings in relation to risk may differ for different populations.” 

Say What? BMI may not correspond to the same degree of fatness in different populations? What the hell are you talking about? Dividing your weight in kilograms by your squared height in meters is not going to tell you how fat you are. It will tell you your “density” but not your “degree of fatness”. Muscle weighs more than fat for the same unit of volume. This means that you can have all kinds of muscle, but still be considered fat/obese by the World Health Organization.how_it_works_muscle_fat1



I am currently 188 @ 5’8. That puts me at a BMI of 28.6. That means that I’m pre-obese/overweight. I’m not saying I couldn’t lose a few pounds, but according to this, I would need to lose 24 pounds to be under 25 BMI. I would be sickly. What is even more scary, if I wanted to go for “Mild Thinness” I would need to weigh 112lbs!


A Better Formula:

There isn’t an ideal formula currently, but I do plan on doing some research and finding one or developing one. Currently the best predictor of health is your waist size. I like using the height to waist size. Measure your waist size and divide it by your height. You want the ratio to be below .50, or your waist size in inches less than half your height in inches. Waist size is a great predictor of heart disease, high blood pressure, and other ailments.


So all in all, F&CK the BMI!



Dustin Holston

Sports Nutritionist/Personal Trainer


Nutrition and Personal Training

Certified Personal Trainer, Nutritionist, MBA, and Firm Administrator of a Law Firm.

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