Effect of an mHealth-assisted multifaceted lifestyle intervention on body-mass index, hepatic fat content and stiffness in children with overweight or obesity: a cluster randomised controlled trial

Background: Lifestyle modification represents the cornerstone of the prevention and early management of obesity, hepatic fat content and stiffness in children. We aimed to evaluate the effectiveness of an mHealth-supported multifaceted lifestyle intervention on body-mass index (BMI), hepatic fat content and stiffness in children with overweight or obesity, and to estimate its potential long-term macroeconomic benefits. Methods: In this cluster randomised controlled trial, six primary schools in Ningbo, China, were randomly assigned (1:1) to an intervention or control group. Children aged 8-10 years with overweight or obesity were enrolled. The intervention integrated school-based health education and polices, physical activity promotion, dietary guidance delivered by clinical nutritionists, and supportive mHealth components. Primary outcomes were changes in BMI, controlled attenuation parameter (CAP), and liver stiffness measurement (LSM). Intention-to-treat analysis was performed using generalised linear mixed models accounting for school-level clustering and adjusting for baseline outcome values, age, and sex. A post-hoc macroeconomic simulation projected long-term economic effects. This trial is registered with ClinicalTrials.gov, NCT05482191. Findings: score 9.1% of the intervention's effect on CAP (both p < 0.05). No adverse events were reported. Macroeconomic modelling suggested that national implementation could yield cumulative economic gains of approximately RMB 694.96 billion (US$ 97.47 billion) during 2026-2050. Interpretation: The mHealth-assisted lifestyle intervention significantly improved BMI, hepatic fat content and stiffness in children. The accompanying macroeconomic benefits support its integration into national public health and economic strategies. Funding: Major Science and Technology Projects for Health of Zhejiang Province; Cyrus Tang Foundation 2022.