From what i have studied.....
The longer fast are healing fasts where the shorter fasts are symptom relief fasts. Long fasts completely tune the engine which makes it much more efficient. This make the car last LONGER..... ergo live longer!
It will not take as much food to keep the engine running after a long fast.
And, on top of that, if you are eating a much healthier diet, the new cells you create will last longer and stay viable longer meaning they wont need to be replaced so often.
Long fasts are for a complete life style change.
Mine is to prevent cancer. Fasts can cure cancer because the first set of cells used in the body during a long fast (after day 15 or so) are the tumors and pre-cancerous cells. The body just eats them right up as fuel. I smoked for 32 years and quit a year ago. In all my readings about cancer cure centers, doctors were pleading with people to do the "complete fast" while they were healthy. It is so hard to do when you have one foot in the grave. I also have mild arthritis and this is used as fuel during a fast. Two birds with one stone.... :-)
Anyway... just what I have read...