With mounting appreciation of the complexity of chronic disease, there is a growing need to understand the systemic causes of current health trends. This will support the development of a prevention system and the use of systems thinking to achieve better, more equitable and more sustainable health outcomes. With new language and a need to change our thinking, the push towards systems practice in preventive health is challenging, and calls for a method to support its application. Group model building (GMB) is a participatory approach that is widely used to build the capacity of practitioners to think in a systems way. However, it is a resource-intensive approach that requires high-level buy-in and the investment of time. We discuss the evidence, including a systematic review of the literature examining the effectiveness of GMB approaches across a wide range of contexts. The results of the review are generally positive and suggest that GMB improves problem understanding, increases engagement in systems thinking, builds confidence in the use of systems ideas and develops consensus for action among diverse stakeholders.