Effects of Parent-Involved Digital Health Interventions on Adiposity-Related Outcomes and Behaviors in Children and Adolescents With Overweight or Obesity: Systematic Review and Meta-Analysis.

BACKGROUND: Parental involvement in obesity interventions is considered essential for sustainable behavior change in children and adolescents with overweight or obesity; yet, the effectiveness of parent-involved digital health interventions (DHIs) and the influence of different delivery modalities remain unclear. OBJECTIVE: This study aimed to synthesize the effects of parent-involved DHIs on adiposity-related outcomes and behaviors and explore potential moderators. METHODS: Nine databases were searched from inception to December 2025 to identify eligible randomized controlled trials (RCTs). Primary outcomes were adiposity-related outcomes such as BMI; secondary outcomes were adiposity-related behaviors, including dietary behavior, physical activity, and sedentary behavior. Standardized mean differences (SMDs; Hedges g) on primary outcomes were pooled using random-effects models. Prespecified subgroup analyses examined DHI delivery modalities and parent-involved strategies. Secondary outcomes were synthesized narratively. Risk of bias was assessed using the revised Cochrane Risk of Bias tool for randomized trials (RoB 2), and certainty of evidence was evaluated using GRADE (Grading of Recommendations, Assessment, Development, and Evaluation). RESULTS: Twenty-nine RCTs (4156 participants) were included, of which 22 contributed to the meta-analysis. Parent-involved DHIs produced a small but statistically significant reduction in BMI-related outcomes compared with controls (SMD=-0.11, 95% CI -0.19 to -0.04; P=.004; I²=0%). When stratified by control type, the pooled effect remained significant in trials using inactive controls (SMD=-0.15, 95% CI -0.25 to -0.04; P=.006; I²=0%), but not in trials using active controls (SMD=-0.07, 95% CI -0.19 to 0.04; P=.20; I²=0%). Subgroup differences on DHI delivery modalities and parent-involved strategies were not statistically significant. For adiposity-related behaviors, significant improvements were reported in 5 of 16 trials for dietary behaviors, 2 of 17 for physical activity, and 2 of 12 for sedentary behavior. The risk of bias was generally low to some concerns, and the overall certainty of evidence for BMI-related outcomes was moderate. CONCLUSIONS: Moderate-certainty evidence suggests that parent-involved DHIs may produce a small improvement in BMI-related outcomes among children and adolescents with overweight or obesity. However, evidence for improvements in adiposity-related behaviors remains limited, and neither the optimal digital delivery modality nor the most effective parent-involved strategy has been established. Future research should refine these interventions to identify optimal strategies and confirm their effectiveness. TRIAL REGISTRATION: PROSPERO CRD420251239829; https://www.crd.york.ac.uk/PROSPERO/view/CRD420251239829.