Objective: Overweight has become a public health problem in most developing countries. Evidence suggests that adolescence is a critical period in determining adulthood obesity and its complications. The present study was carried out to assess the prevalence of overweight and obesity among secondary school students.
Design and setting: This descriptive study was conducted in Tehran city, 2000-2001. Body weight and height were measured and body mass index (BMI) values were calculated. Underweight, overweight and obesity were defined as <5th, > or = 85th and > or = 95th percentile, respectively, of age- and sex-specific BMI values from the National Center for Health Statistics/Centers for Disease Control and Prevention (2000).
Subjects: Using a multistage sampling method, 2321 students (1068 males and 1253 females) aged 11-16 years were assessed in Tehran, the capital city of Iran.
Results: The overall prevalences of overweight and obesity were 21.1 and 7.8%, respectively. The prevalence of overweight among girl students (i.e. 23.1%; 95% confidence interval (CI) 20.8-25.4) was significantly higher than that among boys (i.e. 18.8%; 95% CI 16.5-21.1, P=0.01) even after adjustment for age (odds ratio 1.26, 95% CI 1.03-1.55, P=0.02). No significant risk of obesity associated with age was found in girls or boys. In both sexes, median values of age-specific BMI in this study were statistically higher than corresponding values collected in Tehrani adolescents 10 years ago (P=0.03). Similarly, a significant difference was seen between girl students in this study and the reference population (P=0.03).
Conclusion: According to this study, overweight, especially in girls, should be considered an epidemic health problem among adolescent students in Tehran.