Background
: The purpose of this study was to find changes in percentage obesity and the factors associated with the changes after its treatment in obese children and adolescents.

Methods : A total of 42 obese children from 3- to 17- year-olds (males 60%) were enrolled in an obesity treatment program at least 3 times. They were provided with an individual weight control program that included dietary, activity, and behavioral change information. The paired t-test, Kruskal-Wallis test, Mann-Whitney test, and linear regression were used for analyses.

Results : The means of BMI, percent body fat, and percent obesity were 27.4 kg/m², 39.4%, and 52.3%, respectively. Among them, 85.3% of obese children had one or more abnormalities on biochemical tests and 32.4% of them had 3 or more abnormalities. There was a significant reduction in weight (1.4 kg), BMI (1.1 kg/m²), percent body fat (1.8%) and percent obesity (7.1%), whereas height increased significantly by 1.3 cm after the treatment. The decrease in percent obesity was associated significantly with the number of follow-up, the number of accompanied biochemical abnormality, and the duration of treatment. The decrease in percent obesity was 12.9% among obese children who were followed-up 6 times or more, by 12.2% among those who did not accompany biochemical abnormality and by 13.3% among those who were retained in the program for 76 days or over. However, the change in % obesity was not associated with sex, age groups (＜12, ≥12-year-old), severity of obesity and parental obesity. The percent obesity decreased by 5.2% as the number of follow-up (n=3/4, 5/6∼17) increased after adjusting for sex, age groups and the number of biochemical abnormalities. The number of follow-up also explained 38% for the variance of change in percent obesity in that model.

Conclusion : Continuous program retention was an effective factor to reduce percent obesity. Therefore, further investigation is needed to develop methods to enforce program retention.