When I first began fasting, I would do one day a week. Usually on a Monday. I was in my 20's and my weekends were usually heavy. This continued for about 5 years and it worked out fine. However as I got into my 30's I had children and my fasting routine was about once a month for 2-3 days. I was usually consistent but some months I would take off depending on the activities. In my 40's I resorted to 1-2 weeks every quarter. This was good for me and kept me in top shape. I never had problems with detox symptoms and I never had health concerns. I was also only juice fasting at the time. I currently Water Fast every other month for 3to 5 days. I have gone 15 days on water and find it very debilitating on my body. I have no health issues therefore, I have no need to go that long. I find the 3-5 days every other month is working for me...for now. I fast simply to maintain discipline with my eating. I find fasting eliminates cravings for Sugar and processed foods along with the junk food that's so heavily advertised. I still have no health issues and I attribute that to sensible eating and fasting as a lifestyle.