Effectiveness of obesity interventions among South Korean children and adolescents and importance of the type of intervention component: a meta-analysis

BACKGROUND: Various interventions have been tested to prevent or treat childhood obesity in South Korea. However, the overall effect of those interventions is unclear, as very few reviews and meta-analyses were specific to Korean children and adolescents. PURPOSE: We aimed to examine the overall effect of obesity interventions among Korean children and adolescents, while also examining differences by sex, age group, baseline weight category, intervention duration, number of intervention components, and type of intervention components. METHODS: A meta-analysis was conducted for all intervention studies sampling Korean children and adolescents, with at least one control group and one month of follow-up, published between January 2000 and August 2020. Cohen d was calculated as an effect size for treatment effect, using the standardized difference between intervention group’s body mass index (BMI) change and control group’s BMI change. RESULTS: The final sample included 19 intervention studies with 2,140 Korean children (mean age, 12.2 years). Overall, interventions were strongly favored over their controls (d=1.61; 95% confidence interval [CI], 1.12–2.09). The subgroup analysis showed that interventions with at least one physical activity component (d=2.43; 95% CI, 1.63–3.24) were significantly better than those that did not include physical activity (d=0.02; 95% CI, -0.26 to 0.31). CONCLUSION: Type of intervention component appeared important, though no differential association was observed by sex, age, baseline weight category, intervention duration, and number of intervention components. Korean and non-Korean interventions may be substantively different. Additional studies are needed to understand why and how Korean interventions differ from non-Korean interventions.