just came off my 36 hour fast of just water only, and i really dont know if there is any correlation but my headaches today are much better then they were the 2/3 days leading up to the fast, they have been on and off for the past 2/3 months though,
just thought i'd share, fasting does have some great healing benefits,

for my next one i plan to do a 24 hour dry fast, not sure if i can make it that long without water but ill see what happens,

I do intermittent fasting (12-20 hours w/o food) usually everyday. I find my head feels very clear in the morning before eating.

You may be interested in something called dry fasting, which is explained towards the end of this podcast. I've personally never tried it, but one day I hope to, as well as increase the lengths of my fasts. My problem is that I usually go hypoglycemic around the 13-15 hr mark.

Ian Clark Podcast

I think I remember Mark Sisson saying that it is only "necessary" to do longer fasts at a maximum of once per week.

Thanks for sharing. Keep us updated.

currently 12 hours into a dry fast, no food or water, I am attempting 24 hours but might just go 18 as I want to eat at some point later today, headaches have been pretty good this past week, so tomorrow morning will be interesting when i wake up and see what happens,