Standardized percentile curves of body mass index of Iranian children compared to the US population reference.

OBJECTIVE: To present standardized percentile curves of body mass index (BMI) for Iranian children, and compare these to the US population reference. SUBJECTS: 1599 boys and 1702 girls aged 2-18 y living in urban Tehran as a part of a random cluster sample survey of 1 in 1000 families throughout Iran. MEASUREMENTS: Heights (cm) and weights (kg) were collected by trained health staff. RESULTS: Standardized BMI reference curves for Iranian boys and girls were constructed. The curves are shown to fit the data well. The development pattern of BMI for boys and girls are compared. CONCLUSIONS: The major differences observed between Iranian and the US BMI charts underline the need for population-specific reference data. For children over six years the 5th and 95th percentiles of our data may be used provisionally as cut-off points for defining thinness and obesity for Iranian children and adolescents.