Scaling up a community-led health promotion initiative: Lessons learned and promising practices from the Healthy Weights for Children Project.

The increase in overweight and obesity among children has emerged as an important public health issue. This trend has highlighted the need for accessible and novel approaches to support healthy weights for children and their families to prevent childhood obesity. The purpose of this article is to describe the iterative development and scale-up of a community-led, national-level project to promote healthy weights among Canadian children and families who may be experiencing vulnerabilities. In this project, the Healthy Together program was designed to engage families in an interactive program to support healthy lifestyles. The program also provides a platform for creating supportive environments for healthful lifestyles through practice and policy change. Based on a process evaluation, we describe the iterative development of Healthy Together from Phase 1 through 3 to shed light on processes shaping implementation and scale-up of the program. Lessons learned during each phase were used to refine the program and further expansion. Indicators of successful scale-up include the Healthy Together program's cross-jurisdictional reach and promising evaluation results in real-world conditions. The practice-based program scaling approach provides practical guidance for planning and implementing similar health promotion programs in diverse communities.