Are you at a healthy weight?

Every few years it seems health authorities subtract a few more pounds from what they advise is a healthy weight, and here they go again. Body Mass Index is a number derived from your height and weight. It provides a handy measure of "fatness" and is not gender specific. Before 1998, the range for a "healthy" BMI was thought to be 23 to 27; in 1998, "healthy" was reduced to 18.5 to 24.9. Now, a Harvard University study suggests that those of us whose BMI falls between 22 to 24.9 have a little work to do to avoid the health risks associated with being overweight.

According to the study, the risk for both men and women of developing diabetes, gallstones, hypertension, heart disease, and stroke increased with how much one was overweight. No real news there, but here's the clincher: the relationship between BMI and the risk of developing chronic diseases was evident even among those of us who were recently considered to be lean enough to avoid problems: those in the upper half of the previous healthy weight range. And the findings are not of simply a slight margin of difference. For example, a woman in the high end of the previous healthy range has double the risk of developing diabetes as compared to her leaner counterparts, and a man in the high end of healthy has a 90% greater risk of colon cancer. The authors concluded that adults should try to maintain a BMI of 18.5 to 21.9 to minimize the risk of disease.

Medical experts are likely to argue about this one for a while before formal recommendations are changed. BMI itself leaves out lots of relevant information including activity level, fitness, muscle mass and percent body fat. Regardless though, the issue is a serious public health question since there is no doubt that we are in the midst of an epidemic of obesity and overweight Americans, starting even among children. While there is plenty of evidence to suggest that overweight but "fit" people have lower risks than the overweight and sedentary people, it is a wake up call--extra pounds come with serious health risks. If your numbers suggest a little subtracting in order to fall within the recommended BMI range of 18.5 to 21.9, visit www.eatright.org for information on diet and weight loss or to find a registered dietitian. As a regular runner, you're already way ahead of the game.

(Archives of Internal Medicine, 2001, Vol. 161, No. 13, pp. 1581-1586)

RELATED ARTICLE: Calculating your BMI

Use a calculator to perform this simple but cumbersome formula. Body weight in pounds X 705/Height (in inches) squared. Using a 165 pound, six foot tall individual: 165 X 705/72 squared = 116325/5184=22.4. And the bad news is that the 6 feet tall, 165 pound individual is slightly overweight by the new standards. You can skip the math by going to http://www.nhlbisupport.com/bmi/bmicalc.htm and plug in your height and weight.