NEWS

Ameasure of obesity in children and adolescents that could replace body mass index (BMI) has been identified in a new study as waist circumference-to-height ratio. This detected excess fat mass and distinguished fat mass from muscle mass in children and adolescents more accurately than BMI. The study, published in Pediatric Research, was conducted in collaboration between the universities of Bristol, Exeter and Eastern Finland.

The authors say that, for nearly a generation, weight-to-height ratio charts and BMI for age and sex have been used to diagnose children with obesity. However, these assessment tools are inaccurate in childhood and adolescence as they do not distinguish fat mass from muscle mass. Two children with similar BMI might have different proportions of fat and muscle mass, which makes obesity diagnosis difficult.

Tools such as the DEXA scan accurately measures fat and muscle content of the body, but this device is not readily available in primary healthcare centres. Recently, the American Academy of Pediatrics published a clinical guideline on childhood obesity and requested urgent research on inexpensive and accurate alternative measures of obesity. Emerging studies in adults appear to suggest that waist circumference-to-height ratio predicts premature death better than BMI and could be a potential added tool to BMI measure in improving the diagnosis of obesity. However, there has been no evaluation of how much waist circumference-to-height ratio measurements agree with DEXA-measured fat mass and muscle mass during growth from childhood to young adulthood.