The BMI index is widely used as an indicator of health and is seriously flawed. More on that in a future post.
“Compared to Caucasians, African-Americans of the same age, gender, waist circumference, weight and height may have lower total and abdominal fat mass,” said principal investigator and study leader Samuel Dagogo-Jack, MD, professor of medicine and chief, Division of Endocrinology, Diabetes and Metabolism, University of Tennessee Health Science Center, Memphis.
A person may pay more for insurance if they are categorized as being unhealthy based on their BMI number.
National data show that blacks have higher rates of obesity and type 2 diabetes than whites. Dagogo-Jack and his co-workers therefore examined whether the relationship between body fat and BMI would differ by race. In a study funded by the National Institutes of Health and the American Diabetes Association, they compared how close BMI was to body fat directly measured by DEXA in whites and blacks. The researchers performed the same comparison for waist circumference and abdominal fat.
So the data shows one group as suffering from higher rates of obesity – but is it because they are unhealthier? The not so surprising conclusion:
The correlation between DEXA-measured total fat and the BMI was higher in whites than blacks, the authors reported. The same was true for the correlation between directly measured abdominal fat and waist size.
Therefore, body fat is likely to be lower in blacks than in whites of the same weight and height, Dagogo-Jack said. He said their data suggest that muscle mass may be higher in blacks, which would explain the dissociation between weight expressed as BMI and measured body fat.
Many athletes and individuals in excellent shape are categorized as obese by the BMI standard. In this case, an entire group of people are falsely maligned as being unhealthy. The BMI chart needs to go the way of the dodo, fast.