BMI Measurement Neglects 25 Percent of Children Who Should be Considered Obese

A new Mayo Clinic study found that physicians using Body Mass Index to diagnose children as obese are missing 25 percent of the children who carry extra fat and should be considered obese too.

Childhood obesity is a major concern as studies have established that excess body weight increases the risk of type 2 diabetes as well as other cardiovascular diseases.  This study highlights that physicians are neglecting a major chunk of children who potentially could be at a higher risk of these diseases as they age.  Researchers found that BMI accurately identifies pediatric obesity but it has a moderate sensitivity, suggesting its markers miss those who should be considered obese based on the percentage of fat in the body.

"If we are using BMI to find out which children are obese, it works if the BMI is high, but what about the children who have a normal BMI but do have excess fat? Those parents may get a false sense of reassurance that they do not need to focus on a better weight for their children," says Francisco Lopez-Jimenez, M.D., senior study author and director of preventive cardiology at Mayo Clinic, Rochester, Minn.

The meta-analysis was based on 37 studies that observed 53,521 patients of ages 4-18. This is the first study that assessed the diagnostic performance of BMI to identify excess body fat and compared it with techniques that are considered reference standard to measure obesity.

These techniques include skin-fold thickness measurement and dual-energy X-ray absorptiometry that measures the body composition as well as fat content.

The first author Asma Javed reveals that this study highlights concerns that at risk children are being neglected. 

The finding was documented in Pediatric Obesity.