<p>Protocol for developing the change theory.</p>

Youth face interconnected constraints: unemployment, inequality, limited access to resources and information, and a lack of training. These systemic challenges hinder their effective participation in agri-food systems. This study builds on previous studies, two scoping reviews, and stakeholder consultations, whose outputs were used to develop a Change Theory (CT) for youth inclusion and empowerment in agri-food systems in sub-Saharan Africa. A transformation in four interlinked change domains, namely (a) knowledge, awareness, attitude, and skills, (b) political will, (c) policies and (d) partnerships, is proposed. These change domains are mutually reinforcing and contribute to achieving Sustainable Development Goals 2, 8, 10, 13 and 17. Our proposed CT highlights that youth participation in agri-food systems necessitates a systematic, integrated, and context-specific strategy, fostered by collaboration and coordination among stakeholders across all aspects that affect youth well-being, development, and empowerment. It provides an initial starting point for developing a theory of change or contextualisation to guide the design of interventions, highlighting pathways for addressing challenges within institutional arrangements that affect the implementation, efficiency, and effectiveness of policies on the ground, enabling transformation.