The importance of food systems’ transformations worldwide in order to achieve sustainability is recognised at all levels and scales, and the assessment of the said sustainability appears as a central element to understand the very aspects that need transforming. In parallel, the territorial scale is increasingly seen as the right one to produce such transformations, both in the scientific literature and in policy debates. There has been a proliferation of sustainability assessment methods and tools over the past couple of decades. Yet, researchers agree that these have been mostly unable to support the aforementioned transformations. A post-normal outlook may help in doing so, and it is of interest to identify the aspects that can help rendering assessment coherent with post-normal science. We identify three central categories that can help in doing so, and should thus be considered as central elements in sustainability assessment of Food Systems. These are interdependencies between system components, the system’s trajectories and actors’ participation. We draw elements from the scientific literature to justify the importance of these elements, and carry out a focused literature review of Food System sustainability assessment at the territorial scale to see the extent to which the methodologies proposed incorporate them.