Sugar-induced hyperphagia: is hyperinsulinemia, hypoglycemia, or any other factor a "necessary" condition?

Results of a number of studies have suggested that hyperinsulinemia and resultant hypoglycemia are part of a sequence of responses that can lead to hunger and to sugar-induced hyperphagia. However, it is argued in the present paper that neither hyperinsulinemia, hypoglycemia, nor any other factor per se is solely responsible for the hyperphagic effect of sugar or any other feeding effect. Also, the present paper emphasizes the need for caution in attempting to evaluate the role of a given factor in sugar-induced hyperphagia, or any other feeding effect, by eliminating the factor of interest. I have reviewed evidence indicating that the elimination of preabsorptive insulin, which may mediate sugar-induced hyperphagia, actually potentiates other factors that may mediate the same effect.