Natural resources, such as land, phosphate rock and fossil energy, are scarce. Despite their scarcity, these resources are currently inefficiently used in the food system. My aim, therefore, was to understand the combined effects of technical and consumption strategies, such as preventing and recycling waste, recovering waste as bio-energy, and reducing consumption of animal-source food, on resource use efficiency in the food system. With our integrated food systems approach we demonstrated the role that farm animals can play in a resource-efficient food system, the optimal consumption level of animal protein under various circular paradigms, and trade-offs and synergies between diverse optimisation goals. For example, waste prevention reduces land use, but also reduces the potential to recover energy from biomass to reduce the use of fossil energy. Results further demonstrated that with optimal combination of technical and consumption strategies, resource use efficiency can be substantially increased, especially for phosphorus.