Anthropometric measurements and obesity diagnosis in schoolchildren

Aim:  To evaluate whether anthropometric methods such as arm muscle area, arm fat area, Rohrer index, conicity index, and waist‐to‐height ratio and the commonly used body mass index method are suitable for obesity screening in a multiethnic paediatric population. Method:  A cross‐sectional population study was carried out in the city of Ouro Preto, Brazil, in 2006. Schoolchildren (n = 788) aged 6–15 years were selected by the stratified random sampling procedure by the proportion of students according to age and gender in all schools. Nonparametric receiver‐operating characteristic analysis was used to define the cut‐off for obesity for each method studied, using the tetrapolar bioelectrical impedance technique as the reference method. Results:  Arm fat area measurements and Rohrer index were most suitable for adiposity screening in prepubertal and pubertal boys and in pubertal and prepubertal girls, respectively. In postpubertal period, the Rohrer index was the most suitable body fat assessment method in both genders. Conclusion:  Body mass index presented the best balance between sensitivity and specificity only in the prepubertal period and postpubertal boys. Anthropometric measurements, especially arm fat area measurements and Rohrer index, are useful for screening of adiposity in a multiethnic paediatric population.