Systems thinking in public health – developing theory and practice Design, implementation and evaluation of the LIKE programme, a participatory system dynamics approach addressing childhood overweight and obesity in Amsterdam

Adopting a systems thinking approach holds promise for addressing complex public health problems like childhood overweight and obesity. Systems thinking places a strong emphasis on comprehending an entire system, rather than isolated system elements, and on understanding the underlying system dynamics. However, its application in public health is relatively new, necessitating significant advancements to effectively halt the obesity epidemic. To achieve this, a collective effort is needed to further develop systems theory based on empirical data and tailor it for public health practice. This thesis aims to advance knowledge supporting the practical application of systems thinking in public health and generate empirical evidence for future approaches. Methods rooted in participatory system dynamics were employed to guide the Lifestyle Innovations Based on Youth Knowledge and Experience (LIKE) programme, targeting obesity-related behaviours in Amsterdam adolescents aged 10 to 14. Chapter 1 outlines the LIKE programme protocol, while Chapter 2 delves into the development of the ENCOMPASS systems evaluation framework. Chapter 3 focuses on understanding the system influencing obesity-related behaviours in Amsterdam adolescents. Chapter 4 illustrates the process of developing the LIKE action programme, and Chapter 5 outlines the results of the LIKE action programme. Finally, Chapter 6 highlights key lessons learned in implementing a systems approach addressing childhood overweight and obesity in practice. Insights gained from LIKE may contribute to the evidence base on how systems can be transformed to encourage healthy behaviours.