This paper proposes the utilisation of fuzzy logic so as to design a system which models the biological regulator of blood glucose. That system consists of several fuzzy relations, each one of them modeling a component of the biological glycemia regulator, that is, pancreatic insulin production, net hepatic glucose balance, insulin dependent and independent glucose uptake, and kidney function. A set of experiments has been carried out by means of a simulation of the proposed model, checking that fuzzy control provides good results for the studied cases. The system could be a basis for developing artificial glycemia control mechanisms to be applied as a therapy for different pathologies, as well as for the development of simulators and monitors to aid diagnosis.