Towards more impactful co-design: insights from a systematic review of food loss and waste solutions

Co-design, as a component of broader co-production processes, has gained attention in public policy as a means of addressing complex policy challenges. Yet comparative research remains limited on what occurs under participatory and design-led approaches labelled co-design, what policy solutions these processes produce, and how they are expected to generate change. We address this gap through a PRISMA-guided systematic literature review of 38 studies on food loss and waste (FLW). Findings indicate that co-design labels inconsistently reflect participatory and iterative design practices; creative engagement methods remain underutilized. Co-designed outputs remain at ideation and prototyping stages, while interventions often lack a clear theory of change. We introduce a coding scheme to document co-design implementation and propose CIMO (Context, Intervention, Mechanism, Outcome) as an ex ante evaluation heuristic to articulate the theory of change of co-designed interventions. We conclude with a research agenda emphasizing enhanced reporting practice, theory-building, and implementation-focused research.