The systemic investigation of the energy metabolism in the frame of the selfish-brain theory focusses on supply chains. They describe the transport chain beginning with the energy exploration in the remote environment until the energy is consumed by neurons in the brain. Modeling this, the main difficulty consists in the selection of significant core models among the enormous member of known substances and regulatory mechanisms, which are afflicted with considerable uncertainties in general. We supplement the standard bottom-up modeling of certain mechanisms by a deductive approach. Therefore, we investigate general supply chains and deduce indispensable elements in the regulatory mechanisms from available observations. A critical selection of system properties and underlying mechanisms enables us to simulate observations; which cannot be explained by the classical glucostatic and lipostatic theory. These observations are the e. g. nearly constant energy level in the brain, the different responses of the periphery and the brain to atrophic periods and finally the development of diabetes.