With the Sustainable Development Goals (SDG), the countries of the United Nations have set themselves the goal of reducing food waste along the entire value chain by 2030. The aim of the REFOWAS project was to analyze the German agri-food sector with regard to the production of food waste and, in particular, the share of avoidable waste, and to identify and test strategies and starting points for waste reduction measures. The project combines two levels of analysis. The first, a holistic analysis of the German food sector, was carried out with regard to the waste generated by avoidable and unavoidable food waste and the related environmental effects. At the same time case studies were used to examine various subsectors in more detail (fruit and vegetables, baked goods, school meals) and a social empirical study (private households) was carried out. The methods chosen include: technical discussions; round tables; status quo and control measurements; household survey analyses; guided expert interviews; workshops and field tests to validate results and previously established options for action. The sector-wide investigations are largely based on data from the Federal Statistical Office and derived literature values. In the case studies food waste was quantified and reduction measures tested. From the varied and differentiated findings, recommendations for action for actors in politics, business and society could be derived. The results of the project were communicated in particular through the practically tested and evaluated measures, the subsequent information materials such as articles, brochures and video clips, as well as the wide-ranging discussion of results with lectures and workshops (see REFOWAS website - https://refowas.de).