I used to fast often but it gave rise to binge eating afterwards. The longer I fasted was 5 days only water. I wanted to do more but could not study for an impeding exam. I los 11 pounds.
Presently I only water-fast on Good Friday.
Otherwise, I practice sometimes the fast-mimicking diet by Valter Long, very low calories and very little protein for 5 days, bestows the metabolic benefits of fasting, without the drawbacks (excessive weight loss, excessive fatigue).
Ive gone on two week fasts but only when I have had the sensory stimulation of a long ride across the country and I would drink for instance energy drinks with perhaps fruit juice in the morning. Its always nice to see your weight take a dip. I guess I’ve started to learn some moderation coming off a fast by witnessing my desire to chow down and also drink some smoothies coming off a fast that would satisfy my greed for food. It’s amazing to me - how greedy these bodies we have are for sensory stimulation. But we can begin to witness and observe such behavior. I think more than not, we have to treat these bodies as restless children needing some observation and discipline.