The Dangers of "Normal Weight Obesity"

When we conduct health screenings, we often use Body Mass Index (BMI) to determine whether individuals are at a healthy weight for their height. Although we've blogged in the past about the limitations of BMI, it remains an accepted method of measuring body composition.

The Wall Street Journal recently profiled a study out of the Mayo Clinic that reminds us not to place too much emphasis on BMI alone. Researchers found that even when BMI is in the normal range, other risk factors--such as body fat percentage--may pose an elevated risk of heart disease. The result is what the study called "normal weight obesity."

"High body fat among normal-weight men and women was associated with a nearly four-fold increase in the risk of metabolic syndrome--a cluster of abnormalities including elevated blood sugar and blood pressure," according to the Journal article. Researchers also pointed out that a similar pitfall exists regarding cholesterol. Even if an individual's total cholesterol reading is in the normal range, he or she may still exhibit low HDL (the "good" cholesterol) or high LDL (the "bad" cholesterol).

We advise participants in our health fairs to look at all their body composition numbers together. BMI, waist circumference, body fat percentage are all important.

To calculate your BMI, visit the National Heart Lung and Blood Institute. They offer a free online calculator.