Food systems encompass a very broad range of human activities linked in one way or another to food. They relate to our basic fundamental need to eat, play a crucial role in human health and, beyond those basic requirements, also have a major cultural, social and economic dimension. Food is a source of creativity and pleasure as well as a solid pillar of different cultures and religions. It intrinsically links humans and nature. In producing food, human societies transform their environment and have a substantial impact on natural resources (soils, biodiversity, water, and so on), ecosystems and climate. In return, that impact affects food production conditions and access to food. Lastly, food systems generate “wealth” - capital and income – that is distributed among the players in those systems, in various ways depending on the societies that create them, benefit from them or suffer as a result of them. Food systems – and the social bonds they create - are the fruit of a long human his- tory within a given geographical area. As such, they often acts as a matrix for territories and serve to structure their economic fabric. They are highly dynamic, and evolve in response to demographic, economic, natural, political and legal factors. Food systems have substantial effects - both positive and negative - on various embedded scales. On a territory level, they directly or indirectly affect the physical, biological, economic and social functioning of that territory and/or of the communities concerned. It is this position at the cross- roads between the major challenges for humanity - food, health, jobs and the environment - that makes food systems an absolutely crucial brick in the sustainable development wall. CIRAD has been working for decades on food systems in a range of countries. In confirming its priorities, it is committing to continue working to transform those systems, in line with the sustainable development goals.