The global agri-food system faces major challenges of meeting growing food demand in an equitable way, while mitigating environmental impacts such as deforestation, soil degradation and climate change. Voluntary sustainability standards (VSS) have surged in recent decades as a potential instrument to foster more sustainable global value chains and sourcing practices. While the number of VSS impact evaluations is growing, most studies focus on a single outcome dimension. In this paper, we propose a conceptual framework to assess the effects of VSS interventions on sustainable food system outcomes in three dimensions, considering potential trade-offs between them. To illustrate key trade-offs identified in our conceptual framework, we present empirical data from three case studies in Ghana, Rwanda, and Peru. Our empirical results shed light on associations between certification and various outcomes, including agricultural yields and income, biodiversity at farm and landscape scales, female empowerment, and food security. We highlight the importance of balancing trade-offs in multiple sustainability dimensions and assessing VSS performance within the broader policy and landscape context. Our study contributes to ongoing discussions on the effectiveness of VSS in promoting sustainability while highlighting potential trade-offs that must be addressed to achieve more sustainable food systems.