Hello Big Beat,
I concur with Fontys message in reply to your own. Anything beyond 50 to 70 days would need to be supervised by an experienced & qualified fasting practitioner.
Although fasting is extremely safe, crises can develop with an extremely long fast, such as electrolyte deficiencies........
So the need for proper supervision is essential if you go for this length of time.
However, a series of shorter fasts of between 20 to 30 days each, should enable you to reach your goals, interspersed with proper feeding and the breaking of each one for at least an equal number of days, mainly with raw high-water-content foods, which will be important in avoiding any regain in weight lost.
The return of hunger can occur at anytime if the body has completed its work of internal house-cleaning and healing, whether this be a few days or a month or two: it depends on the work the body has to perform before reaching that stage.