Evaluating School‐Based Obesity Prevention Interventions in 6‐ to 12‐Year‐Old Children: A Scoping Review of All Reported Outcomes and Expert Consultation

INTRODUCTION: This scoping review aims to identify all outcomes reported in school-based obesity prevention interventions in childhood. It serves as an essential first step towards developing an internationally agreed-upon Core Outcome Set (COS), which defines what should be measured in all school-based childhood obesity prevention studies, thereby reducing research waste and enhancing the comparability and relevance of future research. METHODS: Four databases (PubMed, Embase, Cochrane Database of Systematic Reviews, and PsycINFO) were searched for published studies on controlled trials of school-based overweight/obesity prevention interventions in 6- to 12-year-olds, from inception until June 2024. Two researchers independently searched for relevant articles, extracted study/intervention characteristics, and reported outcomes. Through multiple meetings and feedback rounds, an international expert panel, including researchers (n = 5), healthcare providers (n = 4; i.e., pediatrician, youth health physician, dietician, psychologist), and a health educator identified unique outcomes underlying all reported outcomes, by reflecting on what was measured irrespective of how outcomes were defined and measured. RESULTS: ) was the most frequently reported outcome (128 studies), then BMI-z (108 studies) and BMI categories (100 studies). Experts identified 69 unique outcomes from all reported outcomes. CONCLUSION: There is substantial heterogeneity in outcomes reported in studies evaluating school-based overweight/obesity prevention interventions in 6- to 12-year-olds, limiting a synthesis of evidence in meta-analyses. This highlights the need for a consensus-based COS to improve the comparability and relevance of evidence of childhood obesity prevention trials.