Why I Like Percent Body Fat Better Than BMI

BMI which is Body Mass Index is a number used to describe your weight in relation to your height. It is calculated with the following formula:

BMI= kg/m squared where kg is a person's weight in kilograms and m squared is their height in meters squared. If your BMI falls between 18.5 and 24.9 you are considered normal while a BMI of greater than 30 is considered overweight.

I remember living on the Marine Corps bases where there were a lot of very MUSCULAR Marines who did nothing but lift heavy weights for their workouts. They didn't like the use of BMI as an indicator of obesity because it doesn't take into account body weight that is fat and body weight that is muscle. Muscle can tip the scale more than fat can, so this is a very valid point.

BMI is so widely used, but is it truly accurate?

I like to use percent body fat myself. This is much more simple and usually it's pretty accurate in most cases. The MOST accurate method of determining body fat is hydrostatic underwater testing which is considered the gold standard for measuring body fat. I use this little handheld body fat tester because it's small and easy to store in my gym. I feel like it is pretty accurate when I compare my numbers to a Smart Scale at the gym.

With my clients I don't really worry too much about BMI, only percent body fat. If they are above 25% for men and above 32% for women, then I know we have some work to do. Most of my athletes fall in the 10-17% for men and 18-24% for women. I write this number down and periodically check to see if they are where they need to be. Below is the American Council on Exercise Body Fat Percentage Chart.

I hope this simplifies things for you as you take note of these numbers. The next time you need a coach or trainer for your next event, message me by clicking HERE!

References:

*http://healthland.time.com/2013/08/26/why-bmi-isnt-the-best-measure-for-weight-or-health/

*Body Mass Index (BMI) In Adults | American Heart Associationhttps://www.heart.org/en/healthy-living/healthy-eating/losing-weight/bmi-in-adults