I've fasted a handful of times in the past. The last time I fasted was during the first week of 2007. Throughout last month, I had been contemplating a recurring fast for the beginning of this year. So far, I've completed 4 days.
Some have asked, "why fast?" The answer, for me, is to help me start off the year in a better spiritual, physical, and mental direction.
From reading and experiencing, I can say that the first few days are the most challenging. I've managed to keep myself hydrated and have avoided the usual headaches (mostly from caffeine and sodium withdrawal). I cannot, however, distance myself from the exhaustion and dizziness that accompanies this phase. I usually take the steps two at a time but not today. The hunger today has not been too bad. Typically, after the third or fourth day, the hunger almost completely subsides. Mentally and spiritually, there are eventual benefits, but initially there is a struggle with irritability and grumpiness. I think I've done better coping with these symptoms.
I've left my fast open-ended, that is, I have no determined end; I will continue until the time feels right to end it. I intend to share some more of my experience in the next few days, touching on more of the benefits I have and hope to experience. I also intend to address the question that some raise about making your fast public.