In this paper, we deploy a practice theory lens to explore how co-design activities have enabled individuals to transition to new and different advocacy, inquiry and engagement practices. The co-design project we describe sought to bring about change in a national network of organisations addressing food poverty in the UK. The aim of the project was to collaborate with young people and adults from different communities of the North of England to co-design tools for gathering stories and enabling advocacy relating to food insecurity. We use a practice theory lens to describe the relationships between co-design activities and transitions in practices of a single participant. The findings show the value of exploring and sharing meanings, practical experimentation and facilitating transitions within participant’s practice. We argue that practice theory provides an analytical framework to understand the impacts of co-design and social design by interpreting the transitioning practices in participants.