Body-mass indicator confuses both physicians and patients

By JODI UPTON, Gannett News Service

http://www.theithacajournal.com/new...ews/148780.html

Detroit Lions quarterback Joey Harrington overweight? Dr. Robert Atkins, late founder of the popular diet, obese?

These are the conundrums that the BMI, or body mass index, has left us with. Currently, it's the most widely used measurement of obesity worldwide.

The BMI is not perfect. It doesn't take muscle mass or fat composition into account, which is why someone overweight can have the same BMI as an elite athlete like Harrington. And illnesses that can cause fluid retention, such as in Atkins' case, can also wreak havoc.

The index was invented in 1835 by a Belgian to calculate body volume. It's pretty simple: your weight divided by the square of your height (on a metric scale). Eventually a scale was added, so the resulting number falls into one of four categories: underweight, below 18.5; 18.5 to 24.9 normal; 25 to 29.9 is overweight; and 30 and over is considered obese.

Originally, the index was thought too confusing for the public and for untrained doctors, but it has caught on anyway.

In Arkansas, starting this month, all schoolchildren will be measured once a year unless they get a parental waiver. Kids whose weights hover in the danger zone get a doctor's referral note sent home. New Jersey is following suit.

And last month, the Archives of Internal Medicine issued new guidelines for doctors saying every patient should be measured -- regardless of the reason for the visit -- and get weight recommendations.

What's more, the scale is set to white body types, according to an 11-year study in the Medical Journal of Australia. "Normal weight" may actually be a higher risk category for people of lighter body types, such as those from Asia, Southeast Asia and the Indian subcontinent.

But despite appeals for a more reliable gauge, the World Health Organization is standing by its BMI charts, calling them "international classifications," in a Lancet article.

Most recommend using the BMI as one measure among several you should go over with your doctor, such as waist circumference. If you have a high BMI but are very fit, your doctor may make no recommendations.

If not, be prepared for a prescription of a better diet and walking and a healthier lifestyle.

Originally published Friday, March 26, 2004