Scientists’ Views on Sustainable Healthy Diets: A Reflection Process Towards a Multi-Disciplinary Consensus

Achieving a Sustainable Healthy Diet (SHD) is one of the goals of public policy programmes to improve human health and the health of the planet. It is a complex objective that requires the participation of all actors in the food system. One group is scientists who are involved in the study of food in a variety of disciplines. This paper aims to analyse the views that Spanish researchers from different disciplines have on the concept of an SHD and the factors that, in their opinion, hinder or facilitate its promotion in Spain. We carried out a Delphi survey structured in three rounds with scientists from Agricultural Sciences, Natural Sciences, Health Sciences, and Social Sciences. The results show that the experts are in agreement that an SHD is based on nutritious food, with low environmental impact, secure, safe, and accessible. They believe that the main obstacle to promoting SHDs comes from the power of the food processing and distribution industry to influence the system and the difficulties governments face in promoting SHDs. They stress that the main areas for action are food education, regulation of the food system, and changing the framework of governance and the relations between actors in the food system. The process of reaching consensus shows important overlaps between disciplines, especially between experts from Social and Human Sciences and Health Sciences, while those in Natural and Exact Sciences tend to be at the opposite extreme to those in Agricultural Sciences.