Thinness, overweight and obesity in a national sample of Iranian children and adolescents: CASPIAN Study

Background This study was conducted to assess the national prevalence of different grades of nutritional status (underweight, normal weight, overweight and obesity) among Iranian school‐students and to compare the prevalence of overweight and obesity using three different sets of criteria. Methods This cross‐sectional national survey was conducted on a representative sample of 21 111 school students including 10 253 boys (48.6%) and 10 858 girls (51.4%) aged 6–18 years, selected by multistage random cluster sampling from urban (84.6%) and rural (15.4%) areas of 23 provinces in Iran The percentage of subjects in the corresponding body mass index (BMI) categories of the Centers of Disease Control and Prevention (CDC), the International Obesity Task Force (IOTF) and the obtained national percentiles were assessed and compared. Results There was no gender differences in BMI, but was higher in boys living in urban than in rural areas (18.4 ± 3.88 vs. 17.86 ± 3.66 kg/m2 respectively, P