Protocol for a digital health-assisted cluster randomised controlled trial to prevent obesity in preschool children in Jinan, China.

INTRODUCTION

Early childhood obesity has become a major public health concern globally. The preschool period (ages 4-6 years) represents a critical window for obesity prevention due to its long-term implications on growth trajectories and behaviour formation. However, existing evidence for effective interventions targeting this age group remains limited and inconsistent, particularly in low- and middle-income countries.

METHODS AND ANALYSIS: The Peking University-Smart Monitoring and Responsive Technology for Early Childhood Health is a cluster-randomised controlled trial designed to evaluate the effectiveness and sustainability of a multi-component, digital health-assisted obesity prevention intervention. The trial involves approximately 980 children aged 4-6 years (middle and senior kindergarten classes) from 14 kindergartens, randomly allocated to either the intervention (n=7) or control (n=7) groups. The intervention spans 9 months, followed by a 12-month post-intervention follow-up. Interventions are delivered across kindergartens, families and healthcare systems. A digital Smart Health Platform is integrated into the intervention to provide health education, real-time feedback and interactive support, enabling personalised health management and promoting parental engagement. Data are collected at baseline, 4, 9 and 21 months. The primary outcome is the between-group difference in changes in body mass index Z-score at 9 months. Secondary outcomes include other anthropometric indicators, dietary intake, physical activity levels and other measurements. In addition, a process evaluation will be conducted to assess fidelity and participant engagement, and a health economic evaluation will estimate cost-effectiveness and cost-benefit outcomes.

ETHICS AND DISSEMINATION: Ethical approval for this study was obtained from the Ethics Committee of the Shandong Maternal and Child Health Hospital (no. 2025-042). Findings from the trial will be disseminated through peer-reviewed publications and conference presentations to inform future childhood obesity prevention policies and practices.

TRIAL REGISTRATION NUMBER: NCT07117149.