LAUSR

PURPOSE Childhood obesity is a major global issue that causes a variety of health problems and high social costs. Many previous studies have investigated childhood obesity using cross-sectional data, but few longitudinal cohort studies have been performed, especially in the Korean population. METHODS We analyzed the incidence and prevalence of obesity and overweight in a Korean prospective cohort study of children that were followed-up from age 7 to age 36. The study eventually recruited a total of 1,216 participants, with 16 follow-up surveys over 30 years (1986-2017). RESULTS The annual incidence of obesity showed a small peak (2.1%) at age 13 when the cohort entered middle school, but a rapid increase (6.4%) when participants reached the age of 20. The prevalence of obesity and overweight at age 8 was 0.8% and 0.9%, respectively, and increased rapidly from age 12 (obesity 2.2%, overweight 4.6%), reaching 9.5% and 15.9%, respectively, at age 20. The prevalence of obesity and overweight was consistently higher in girls than in boys during the childhood period, but this trend reversed in adulthood. CONCLUSION Incidence and prevalence of obesity and overweight increased markedly after the final grades of elementary school in females, but after adolescence in males.