Generation Healthy Kids: a protocol for the mixed methods process evaluation of a school- and community-based intervention targeting healthy weight and wellbeing among 6–11-year-olds in Denmark

Abstract Background A high prevalence of child overweight and obesity worldwide calls for innovative multi-setting intervention approaches, and thorough evaluation. This paper describes the protocol for the process evaluation of the Generation Healthy Kids (GHK) program—a school- and community-based intervention to promote healthy weight and wellbeing among 6–11-year-old children in Denmark. The process evaluation will explore (1) implementation, impact mechanisms and contextual factors influencing intervention outcomes and (2) potential ethical issues and unintended outcomes. Methods GHK aims to promote healthy weight and wellbeing through regular physical activity, healthy eating, improved sleep and balanced screen media behaviour among children in 1st–3rd grade. Intervention development was informed by United Kingdom Medical Research Council guidelines, previous evidence, theory, context knowledge, stakeholder input and a feasibility study. Intervention activities are designed to develop food, digital and physical literacy; awareness of sleep and screen media practices; social cohesion in the school class; and a supportive healthy environment. Pre-defined components in schools include a free lunch program 4 days a week; compulsory 40-min high-intensity physical activity sessions 3 days a week; equipment for active recess; classroom exercises on food literacy, screen media use, and sleep; and workshops and guidelines for parents on children’s sleep and screen media behaviour. Local community interventions promoting child health and well-being will be co-created with community stakeholders. The ‘Supersetting Approach’ will be used to develop coordinated interventions across relevant settings. The 2-school year intervention will be tested in a cluster-randomized controlled trial with 12 intervention schools and 12 control schools, assessed at baseline (autumn 2023), and approximately 6 and 18 months later. The process evaluation will be guided by the project’s program theory, process evaluation- and implementation science concepts and system approaches. It will include quantitative and qualitative methods and perspectives of children, parents, school staff and community stakeholders. Discussion The process evaluation will facilitate (1) interpretation of intervention effects; (2) understanding of context, impact mechanisms, synergies, implementation issues and evaluation approaches related to combining pre-defined components with system approaches and co-created activities; and (3) refinement of intervention and implementation strategies prior to potential scale-up. Trial registration ClinicalTrials.gov: NCT05940675. Registered on 4 July 2023.