PROTOCOL: Effectiveness of Interventions for the Prevention and Treatment of Obesity in Children and Adolescents From Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis.

Childhood obesity represents a major and growing public health challenge, with a disproportionate burden in low- and middle-income countries (LMICs). This systematic review will address a critical evidence gap by synthesising existing research on the effectiveness of interventions for the prevention and treatment of childhood obesity in LMICs. By focusing exclusively on interventions implemented within LMIC contexts, the review will account for the unique socio-cultural, economic, and environmental determinants that influence intervention delivery and effectiveness in these settings. A literature search will be conducted across MEDLINE/PubMed, Embase, CINAHL, and The Cochrane Library, without restrictions on publication date or language. Randomised controlled trials (RCTs) examining interventions for the prevention or treatment of overweight and obesity among children aged 5-9 years and adolescents aged 10-19 years will be included. The primary outcomes will be age-adjusted body mass index (BMI), other measures of adiposity, and the prevalence of overweight and obesity. Secondary outcomes including dietary intake, physical activity, health-related quality of life, and adverse events will be reported narratively but excluded from the meta-analysis. Two independent reviewers will screen the studies, data extraction, and risk of bias assessment. Intervention effectiveness will first be summarised descriptively according to intervention type and key characteristics. Where appropriate, pooled effect sizes will be estimated using a random-effects meta-analysis. To explore and manage heterogeneity, analyses will be stratified by age group (children vs adolescents) and intervention purpose (prevention vs treatment). This review will identify effective strategies for preventing and treating childhood obesity in LMICs and explore the intervention features associated with successful outcomes. The findings will inform policy development and support the design and implementation of contextually appropriate interventions, contributing to global efforts to reduce obesity and prevent non-communicable diseases (NCDs).