The concepts of food security and food sustainability are two main paradigms in the food system discourse—however, they are often addressed separately in the scientific literature. We argue that this disconnect hinders a coherent discussion of sustainability transitions, which will be necessary to solve problems (environmental, social, economic, and health) generated by conventional food systems. Our review highlights linkages between sustainability transitions and food and nutrition security using the perspective of sustainable food systems. We explore the diversity of food security narratives and food sustainability paradigms in the agro‐food arena, analyze relations between food security and food systems sustainability, and suggest options to foster a transition toward sustainable food systems. It is widely acknowledged that food systems sustainability must entail long‐term food and nutrition security in its availability, access, utilization, and stability dimensions. For food systems to deliver food and nutrition security for present and future generations, all their components need to be sustainable, resilient, and efficient. These linkages between food sustainability and food and nutrition security intersect at global, national, local, and household levels. Different strategies can be pursued to foster sustainability transitions in food systems: efficiency increase (e.g., sustainable intensification), demand restraint (e.g., sustainable diets), and food systems transformation (e.g., alternative food systems). Creating sustainable food systems requires moving from an agriculture‐centered to a food system policy and research framework. This will be fundamental to foster the complex and holistic transformation necessary to achieve sustainable food systems, which is, in turn, a prerequisite to achieving sustainable food and nutrition security.