BMI: not so good for measuring the individual

This morning, I heard a story on morning edition (www.npr.org/templates/story/story.php) about Safeway doing innovative things to control healthcare costs. I’m generally in favor of what they’ve done, as I subscribe to the idea that we should encourage what we want and discourage what we don’t want.

However, and this is a pretty big however, one of their methods of determining health (risk, meaning expected cost) is BMI, a measurement designed to measure the “health” of a population and should not be used as a diagnostic tool for individuals (see the weekend edition story here: www.npr.org/templates/story/story.php).

Since I’ve been losing weight recently, I’ll give you some statistics about me to possibly shed some light on this:

At the start of my program, my stats were:

BMI: 33.9
Body Fat: 25%

Interestingly,  I knew someone else in the program who I had always considered to be the same size, shape, build and strength as I am. He is the same height for certain, but I learned something very interesting, his bodyfat percentage was 35%. Our BMI was the same, but by bodyfat, one of us was in much better “health”.

For fun, my current stats are:

BMI: 27.1
Body Fat: 13.5%

The healthy range of bodyfat, at least according to the worlds largest opinion encyclopedia, included my starting point. and puts me currently in the athlete category (I expect by next week I’ll be measured at 12.x%). (en.wikipedia.org/wiki/Body_fat_percentage). So I’m an athlete, which, if you took a look at my level of physical activity is a conclusion you’d likely agree with: yesterday was a “rest” day, so I played a few games of volleyball at the gym, with elliptical trainer in between, ending with 30 minutes on the elliptical for good measure.

If you’re getting the same picture I am, you’re concluding that I’m pretty fit these days.

Now we delve into BMI. According to the Department of Health and Human Services (www.nhlbisupport.com/bmi/), Here are the ranges for BMI:

  • Underweight = <18.5
  • Normal weight = 18.5-24.9
  • Overweight = 25-29.9
  • Obesity = BMI of 30 or greater

My BMI, coming in at 27.1 is smack in the middle of overweight. Wait a minute, I thought I was an athlete, now you’re telling me that I’m overweight? I don’t get it. Let us go back to the creator of BMI suggesting that BMI is an instrument useful in measuring the health of populations in aggregate and not very interesting in individuals.

So, to Mr. Burd (CEO of Safeway) perhaps you’d consider changing your program incentives to be based on body fat percentages?

A few other things to know:

  • Levels of body fat considered to be healthy differ for men and women
  • I’m sorry I cited wikipedia, they cite the American Council on Exercise

Leave a Reply

Your email address will not be published. Required fields are marked *