Applying system dynamics methods for local obesity prevention: results from a group model building study in Amsterdam, the Netherlands

Background: This study aimed to evaluate a participatory system dynamics group model building (GMB) process for local obesity prevention and policy. Methods: GMB workshops with n = 9 to n = 31 participants were held with local stakeholders involved in child health in a community setting in Amsterdam, the Netherlands. The traditional number of two GMB workshops was expanded to a total of five workshops to facilitate the process of system understanding (workshop 1 and 2) and leverage point and action development (workshops 3–5). Also, four thematic sub-groups were installed to work on systems change. We triangulated different data sources to evaluate the outcomes, including stakeholder interviews at two time points. Results: The GMB workshops resulted in a casual loop diagram (CLD) with 30 mechanisms explaining the obesity problem, five potential leverage points for change and 16 action ideas; which were subsequently classified using the intervention level framework. Action ideas targeted system elements (n = 3); feedback and delay (n = 4); structure (n = 8); and goals (n = 1). Interviews revealed the challenge in pushing beyond superficial solutions and instead developing initiatives that can achieve fundamental changes in the underlying system dynamics. Conclusions: Our study is one of the first providing insight into how system understanding can be translated into actionable leverage points and action ideas targeting different system levels. Achieving tangible systems change at system goals or paradigm level requires substantial stakeholder involvement and a dedicated process.