LAUSR

Objective: Studies reported the plateau of the rates of adolescent obesity and its masked socioeconomic inequality in developed countries. However, the burden of pediatric obesity continued to increase in Korea and its socioeconomic disparity remains poorly described. This study aims to investigate the recent trends of prevalence and socioeconomic disparity in obesity among Korean adolescents from 2006 to 2020. Design and method: We used annual data of self-reported height, weight, and socioeconomic information from the nationwide survey, Korea Youth Risk Behavior Web-based Survey (KYRBS), from 2006 to 2020. Adolescent obesity was defined as a sex-specific BMI for age of 95 percentile or greater among children aged between 12 and 19 years. Obesity prevalence was calculated according to each of four socioeconomic indicators (household income; parental education attainment; urbanicity). Also, socioeconomic inequality in it was quantified and compared using Relative Index of Inequality (RII). Identical analyses were repeated for the subgroups by sex or stage of school along with the total study population. The trend analyses of prevalence and inequalities were conducted using linear regression model with the variable of survey year. Results: The analytic sample consisted of 818,210 students, representing approximately 64% of adolescents in Korea. The overall prevalence of obesity continued to increase and doubled during the study period. Male and high school students showed higher absolute figures. Inverse relationships between obesity and socioeconomic status were observed across all subgroups. RIIs in household income and parental education attainments significantly increased with time. These socioeconomic disadvantages exercised greater influence on obesity among female and middle school students. Conclusions: This study showed increasing prevalence and widening inequality in obesity among Korean adolescents. These findings highlight parental educational attainments to understand socioeconomic disparities in adolescent obesity, along with household economic status. Relevant policymaking and intervention should focus on not only lowering the absolute figures among boys and high school students but also narrowing the gap among the disadvantaged girls and middle school students.