Background
: The purpose of this study is to obtain the accurate information the obesity indices, such as body mass index(BMI), relative weight and waist-hip ratio(WHR) and to investigate their relationship in order to assess the childhood and adolescent obesity more appropriately.

Methods : In May, 1995, a total of 6943(male ; 3469, female ; 3474) students from primary, middle and high schools in Seoul were selected and each students' height, weight, waist and hip circumference data were collected.

Results : The BMI increased with age in both sexes. From age 12 to 16, values of BMI 50th percentiles for females exceeded those for males. And the BMI 95th percentiles at the age of 13 to 14 years were higher for females than for males. The prevalence of obesity by relative weight was higher in males than in females(male ; 17.9%, female ; 13.1%). The WHR was higher in males than females in all age group and decreased with age in both sexes, showing more sharp reduction in females. Strong correlations were observed between the BMI and the relative weight, and the BMI and the relative weight correlated closely with WHR. The WHR was significantly higher in obese group than in non-obese group. In the female obese group aged 6 to 11 years, no significant correlation was found between the relative weight and the WHR.

Conclusion : There were significant relationships between he indices of obesity and body fat distribution. This study suggests that WHR as well as BMI and relative weight might be useful in assessing the childhood and adolescent obesity.