Re: weight gain.

Bling,
consuming sea-salt during a fast is really breaking the fast, as this constitutes external feeding.
I know for certain that Dr Fuhrman has terminated fasts prematurely, and before the onset of hunger because of a low electrolyte level, so it doesn't always follow that the body will recognize that deficiency, resulting in the return of hunger.

I personally think he was erring on the safe side, when to have continued would have been safe. It would take a broad spectrum of nutrient-deficiency before the body reacts and hunger returns.
My own first fast of 25 days was terminated for this very reason, although I felt fine towards the end as this deficiency materialized.

Regards

Chrisb1.