What makes digital health work? The role of intervention structure in childhood obesity

Abstract

Abstract Background Childhood and adolescent obesity remain a major public health challenge worldwide. Although widely adopted, digital health interventions have shown inconsistent effectiveness. Limited attention has been given to how interventions characteristics, including behavioral mechanisms and integration with non-digital components, influence outcomes. This study examined the structural features of digital health interventions and their relationship with effectiveness. Methods A scoping review was conducted following PRISMA-ScR guidelines. Interventions were analyzed using a novel structured framework across three dimensions: modality (“What is used”), behavioral mechanisms (“How it works”), and integration (“How components are integrated”). Family engagement, digital role, and sex-specific findings were also assessed. Results Of the twenty-three studies, ten (43.4%) showed significant or partially significant effects. Exergame-based interventions demonstrated higher effectiveness (66.7%) compared to AI-based approaches (33.3%). Mechanisms involving social support (77.8%) and behavioral activation (57.1%) were associated with greater effectiveness, than self-monitoring and nudging. Hybrid-integrated interventions demonstrated higher effectiveness (54.5%) than fully digital approaches (20.0%). Family-engaged interventions showed higher effectiveness (70.0%) compared to those without family involvement (23.1%). Limited sex-specific analyses suggested greater weight-loss benefits among girls. Conclusions Interventions embedded in digital, social, and care delivery systems appear more effective, highlighting the importance of system-level design in obesity prevention and management. Future digital health interventions should be designed as adaptive, integrated systems that leverage coordinated support across family, school, and healthcare settings. Future studies should also evaluate sex-specific responses to inform more personalized interventions. Key messages • The effectiveness of digital health interventions for childhood obesity depends on how they are structured and integrated, rather than on technology alone. • Interventions embedded within interconnected digital, social, and care delivery systems appear more effective, highlighting the importance of system-level design in obesity prevention and management.