Construction of a New Reference Data for Body Mass Index of Schoolchildren in Yazd (Iran)

Background: Monitoringandevaluating physical growth in children is an importantwayto determine their nutritionalandhealth status. Health personnel can diagnose growth impairment and malnutrition in children by growth monitoring from growth indices. Objectives: This study aimed to determine the cut-off points of body mass index (BMI) in children and adolescents and compare them with the National Center for Health Statistics (NCHS) standards. Methods: In this cross-sectional study, 4,320 students (6 - 11 years old) were selected by cluster sampling in 24 primary schools. A class (a cluster) was randomly selected from each base in each school. Then, 30 students from each class were randomly selected. The height and weight of students were measured, and then BMI was calculated for students. After data collection, height, weight, and BMI tables were calculated based on age and sex and compared with theWHOstandards using the LMSchartmaker Pro software 2.3. Results: The results showed that height, weight, and BMI percentiles in both gender were close to NCHS standards features in all ages, but some percentiles were higher in children in Yazd than NCHS standardsNCHS standards, including the 97th percentile of height for boys, the 97th percentile of BMI for both gender, the 97th percentile of weight for boys, the 75th percentile of weight for boys aged 9 and 10 years, and the same percentile in girls ages 7 - 11 and 9 - 11 years, respectively. Conclusions: According to the results, the researchers recommend using the indices of the present study according to the differences observed between height, weight, and BMI in children studied with NCHS standards.