Changes in Overweight Prevalence among Tehrani Children and Adolescents: Comparison of Three Different Definitions

There are so far few comparisons of the prevalence of obesity according to the type of definitions and, therefore, more reports are required to show the diversity of obesity patterns across countries with different economic development and cultural background. The objective of the present study was to assess the prevalence and trends in overweight among Iranian children and adolescents using three different definitions. Patients & Anthropometric measurements were assessed in two population-based cross-sectional studies of children and adolescents aged 3-19y in 1998(n=4528) and 2001-2002(n=2037) within the framework of Tehran Lipid and Glucose Study. Overweight was defined as ≥95th percentile of BMI for age and sex based on: 1) standardized percentile curves of body mass index(BMI) suggested for Iranian children and adolescents, and 2) 2000 centers for disease control and prevention growth charts. The prevalence of overweight using age-and sex-specific cut-points suggested by International Obesity Task Force(IOTF) was also estimated. Using Iranian cut-points, the prevalence of overweight was approximately 3% for 3-5y and 12% for 6-11y and 12-19y in 1998. These estimates rose to 4, 19 and 16%, respectively, in 2001-2002. Using CDC2000 cut-points, the prevalence of overweight among age categories of 3-5, 6-11 and 12-19y were approximately 3.5, 6 and 7%, respectively, in 1998, which rose to 6, 10 and 9%, respectively, in 2001-2002. Overweight, as defined by IOTF cut-points, was prevalent among 2% of 3-5y, 4% of 6-11y and 5% of 12-19y in 1998, which increased to 4%(P=0.20), 6%(P=0.02) and 7%(P=0.01), respectively, in 2001-2002. In the age categories of 6-11 and 12-19y, estimates obtained from Iranian cut-points were higher than those obtained by using CDC2000 or IOTF, whereas in the 3-5 age category, there was no significant difference between the estimates obtained from Iranian cut-points and those estimated by CDC2000 or IOTF. The prevalence of overweight among Iranian children is increasing. Our findings also reflect the difference in prevalence estimates based on different definitions.