BMI = weight in pounds / height in inches * 703 (to convert from metric)
Take a long hard look at that formula and notice that it can’t tell a damn thing about the condition of your body.
Missing a leg? That will help your BMI.
What about having a dense bone structure? That will hurt your BMI.
Are you in awesome shape? I mean really jacked, like the Governator circa Conan the Barbarian? Yeah, the BMI can’t differentiate between muscle and fat.
The BMI is a horrid measure. There is no room for debate on this one. It can’t tell the difference between fat, muscle, blood, bone, or anything else in your body. It can’t differentiate between two people who are both 5’5 and 140 lbs, but one of them is missing an arm.
Want to read more about the stupidity of the BMI?
Check out this excellent article from NPR – Top 10 Reasons Why the BMI is Bogus
Penn & Teller also did a superb episode on this in Season Five.