In this work extensive misconceptions of university students'--from nutrition area--about the metabolism of carbohydrates (CHM) in the human organism have been documented. The results lead to consider their difficulties concerning the learning of a complex set of imbricated biochemical models involved. Pursuant to these considerations, three physiological models are proposed as conceptual axes around which CHM in the human organism could be taught, in order to avoid fragmentation in students' knowledge and to give simple physiological contexts where to integrate those biochemical models. These contexts are: (a) a physiological model of the carbon cycle, (b) a physiological model of blood glucose uptake and homeostasis, and (c) a physiological model of the availability of small metabolites.