Changes in Prevalence of Obesity and Underweight among Korean Children and Adolescents: 1998-2008

Background: The aim of this study was to investigate changes in prevalence of obesity and underweight [weight, body mass index (BMI), and waist circumference] among Korean children and adolescents. Methods: We analyzed the data of 2,820 subjects aged 10-18 years (1,478 boys and 1,342 girls) from the Korean National Health and Nutrition Examination Surveys conducted in 1998 and 2008. Results: Over the study period, mean values of body weight, BMI and waist circumference were significantly increased in boys; however no significant change was observed in girls. The proportion of overweight (1998 vs 2008; 6.3% vs 14.7%) and obese boys (1998 vs 2008; 4.7% vs 8.2%) were increased, while the prevalence of boys with normal weight was decreased (1998 vs 2008; 82.8% vs 71.4%). No significant difference in the prevalences of normal weight, overweight and obese girls was seen over the study period, however an increasing trend in prevalence of underweight was observed in elementary school girls at the beginning of puberty (1998 vs 2008; 4.8% vs 9.4%). Conclusions: Increasing obesity prevalence in teenaged boys, and emergence of underweight in girls at the beginning of puberty were observed among Korean children and adolescents.