I fast.Water fasts though. I heard the same thing about the 48 hours. I do either a 2 or 3 day fast on a regular basis. Atkins does not clean all of the toxins out if you are not eating hormone or steroid free meat. I do this fast to clean all of that crap out because we eat so much meat with this woe. I never gain the weight back nor does my insulin fluctuate. I have never gone a week though.