Re: How short is the shortest fast?
The body will begin producing ketones after the glucose is gone from the blood, this is supposed to happen between 18-36 hours. The body changes over the next couple of days to a process of autolysis in which it provides complete nutrition from it's own stores. Once that happens it begins cleaning and repairing parts of itself which it has been unable to do as efficiently, or at all, while eating. The healing effect of the body increases up to about day 10 when it starts to settle in for the long haul and will conserve it's reserves to get maximum time available from what it has.
The danger of shorter fasts where the body doesn't actually enter ketosis at all, or fully, is that over time this could lead to some sort of malnourishment. However, given that your diet is (almost) chemical free, healthy and has a greater percentage of highly nutritious raw food than most, this will not be a problem for you.
So, shorter fasts can be dangerous for those who just fast periodically while ignoring the nutritional needs of their bodies, but so long as you are eating well the fast will always be beneficial.
Andrew.