The transition of food-production and consumption systems to a sustainable, low carbon future presents a dauntingly complex issue, involving technical, political, social and theoretical aspects. Such a transition necessitates an exploration of new ways of production and consumption, new technologies and innovations and new regulatory and institutional infrastructures to co-ordinate the change. Appropriate sustainability assessment has the following advantages: the conceptualisation of complex system functioning; the identification of the need for multi-dimensional, strategic approaches; the development of appropriate policy responses; and the targeting and framing of action (assessment) for sustainability. The paper presents a number of key findings and directions for further research in the context of agri-food systems sustainability.