Abstract: Objective: The World Health Organization and other international health organizations recommend the use of BMI to screen for overweight and obese children and adolescents; but the research results might be affected if using different Age-Gender-body mass indexes in different countries as the screening criteria. Methods: In this study, WGOC standards, WHO / NCHS standards and IOTF criteria are adopted to analyze the screening differences of Chengdu urban students’ overweight and obesity aged 7-17, and their overweight, obesity prevalence, sensitivity differences in specificity and consistent rate are also compared using the three standards. Results: WHO / NCHS standards are efficient in screening overweight boys and excluding normal boys, while WHO / NCHS standards are inferior to IOTF criteria in screening overweight girls. Both standards can be different in screening children of different ages in terms of sensitivity and specificity. Both can be effective in excluding overweight children, but both indicate a lower efficiency in identifying obese children, esp, obese girls. Conclusion: on the whole, both are better than IOTF in screening overweight and obese children. WHO/NCHS might be more appropriate to be used in China for screening overweight and obese children.

Key words: body mass index, obesity screen, children and adolescents