Hi William, I would argue that the constant state of mild euphoria in zero carb comes from a steady and ample supply of tryptophan instead of the surges that come from insulin spikes. Zero carb would also reduce the gut inflammation that comes with the SAD. Inflammation uses up serotoinin (which is made from tryptophan) so sub-optimal quantities would be reaching the brain in a person on a SAD, whereas with little or not gut inflammation, there should be ample tryptophan for transport into the brain where ample serotonin production could then take place. There are also some seasonal rhythms that dictate some of our taste preferences - aimed at storing fats for the winter months ahead. best wishes, Ron > Not primordial; Bear calls it acculturation, and in the fat-poor > neolithic most of those who could not get enough starch/carbs died. > > There is also the drug effect described by Ron, which is odd because > those who succeed in raw zero carb describe a constant feeling of mild > euphoria. > > William > -- PK