Research on the Dynamic Energy Budget (DEB) theory started 35. years ago. Initially much emphasis was put on the development of a consistent theory. During recent years attention was paid on parameterizing DEB models for a huge collection of species. This enables the search for patterns in parameter values in an ecological and evolutionary context. This special issue presents some of the results of this quest, among other things focusing on the development of metabolic acceleration, combined with various applications of DEB theory in fisheries, aquaculture, climate science and ecotoxicology.