Book excerpt: There is growing evidence that the current agri-food system is not sustainable, because major environmental and ethical issues challenge the global development. Against this complex background it becomes clear, that sustainable food is a global issue, relevant for individual consumers as well as for the society, for agri-food businesses and policy actors. From a consumers point of view sustainability is a credence attribute and comes on top of an already highly complex buying decision process that can be facilitated by third-party certification and labelling. Over the past decades a number ...