Résumé
In the past decades, we have luxuriously been provided by fossil fuels. They have allowed playing an enormous variety of games to challenge and please us. The number of games has been large – by some considered as endless – however it’s becoming more and more apparent that the number is not unlimited; renewable andrecycled resources as well as solar energy input have their limits. We may question ‘how large?’ That depends on our creativity and passion to play as well as to the new boundary conditions. Examples of the latter are e.g. the limited available fossil fuel resources and the continuous rise in atmospheric CO2 concentrations due to ourdaily requests for more energy. Sea levels rise and weather conditions may change more rapidly and extremely; consequently, this will restrict us to deliberately choose where to live, what to do, produce, consume and utilize. Even more, we are not solely facing environmental and economic constraints, but also social and ethical issues.Unequal global balances in ‘access to and availability of food and healthy diets’ is a key and persistent example of the latter; this leads to food insecurity, malnutrition and stunting for a major part of the growing (demands of the) world population. In this context, the efficient and sustainable transformations of multi-resources intomulti-products should be fully reconsidered. The challenge is to understand in an integrative and systemic manner (1) the nature of those multi-resources-multiproducts, (2) their (bio-)diversity, (3) their behaviour under changing conditions – either being environmental or process-related – and (4) their final configurations(structure-functions of end-products) and their stabilization. Thus, it is neither a single chain approach, nor a network approach, but more a complex systems approach. Some cases are presented based on research outcomes of projects at INRA, Wageningen UR and the European Commission.