The incidence of childhood obesity in Thailand has become increasingly high and its effects are likely to worsen in the future. To control and prevent obesity effectively by behavioral changes, various levels of control and factors are needed. This two-group pretest-posttest non-equivalent control quasi-experiment aimed to compare health behavior and the lost weight among overweight secondary school students before and after the experiment. The subjects of the study were male and female students whose weight was over the standard weight studying in secondary schools in Hat Yai District of Songkhla Province. There were 51 students in each group of the control and the experimental groups. The behavioral change tools consisted of administrative policy, physical environmental development, peer influence, health service systems, parents program, food sellers program, and health behavioral change program for overweight children. The experiment was from July 2014 to February 2015. The general data were analyzed with frequency and percentage, health behavior and weights before and after the experiment were compared using Wilcoxon Signed Ranks Test and Mann-Whitney U Test. Analysis was performed with qualitative data on school administrative policy, physical environmental development, health service system, and food sellers in the school.
The study found that after the experiment, the experimental group had a higher level of health behavior in food consumption than the control group at a statistically significant level of p<.05, the level of health behavior in exercise for the experimental group was also higher than that for the control group at the level of p=.05. The effects of the programs on weight loss revealed that the average of ordinal scale for the experiment group decreased with a statistic significance of (p< 0.05) while that for the control group increased with a statistic significance of (p< 0.05).
The results of the study indicate that the health behavioral change program improved health behavior among the overweight secondary school students, and decreased their weights.