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