Secular trends in weight status and weight-related behaviors in Korean adolescents from 2006 to 2013

The purpose of this study was to examine the secular trends in weight status and weight-related behaviors in adolescents in Korea from 2006 to 2013. Using a repeated cross-sectional design, we analyzed raw data from the 2006 and 2013 Korea Youth Risk Behavior Web-based Survey, which included 69,500 adolescents in 2006 and 70,354 adolescents in 2013. Subjects were 12- to 18-year-old boys and girls from the first grade of middle school through the third grade of high school. The data was collected by using an anonymous self-administered online survey. From 2006 to 2013, the prevalence of obesity increased by 0.7 (percent point; % p) (p < 0.001) in boys and 1.0% p (p < 0.001) in girls. At the same time, the prevalence of obesity increased by 1.0% p (p < 0.001) in middle-school students and decreased by 0.7% p (p < 0.001) in high-school students. Healthy, unhealthy, and extreme weight-control behaviors decreased in all adolescents (all p < 0.001). Obesity and unhealthy weight control behaviors in Korean adolescents remain major public concerns, and programs to encourage healthy weight control behaviors are required.