BMI Out, Body Fat In?

Shape Up America! launches initiative to use body fat percentage as a leading public health indicator.

WASHINGTON, D.C. - Shape Up America!, the anti-obesity initiative started by former U.S. surgeon general Dr. C. Everett Koop, has issued an advisory stating that one's body fat percentage is superior as a measure of healthy weight than the currently accepted body mass index (BMI).

This announcement follows new research supporting body fat percentage as an indicator of health risk. Notably, investigators from the Obesity Research Center at St. Luke's-Roosevelt Hospital Center in New York City, as well as clinical centers in the United Kingdom and Japan, correlated body fat percentage to BMI, taking the first big step toward linking body fat percentage directly to disease risk.

In a press release, Shape Up America! pointed out the shortcomings of BMI, a mathematical formula based on a person's height and weight. Specifically, BMI can't distinguish fat from muscle. This can lead to misclassification. For example, highly muscular individuals may have a high BMI, leading to the conclusion that they are obese when, in fact, they are heavy because of muscle mass. Conversely, an individual with a healthy BMI (i.e., 18.5 to 24.9) may, in fact, have a dangerous level of fat content.

Since body fat percentage is able to distinguish fat from muscle, it is a more direct assessment of healthy weight, according to Shape Up America!. By announcing its body fat initiative, Shape Up America! hopes to inform physicians and the public that body fat percentage gives a better indication of health status such as blood pressure and blood cholesterol levels.

"The new data on body fat percentage are compelling and should be a national call to action," Dr. Koop said in a statement issued by Shape Up America!. "This important finding impacts more than 90 million Americans considered overweight or obese according to current government BMI-based guidelines."

For people who want to take action, Shape Up America! has added a "Body Fat Lab" to its Web site (www.shape-up.org). This new, online feature is designed to identify the healthy range of body fat percentage and the disease risk associated with higher levels of body fat percentage.