Look up Dr. Jason Fung - books and videos. He's got a lot of good resources on starting the process and going from a simpler 16-8 type fast to more extended fasts, though he is careful to indicate that extended fasts should be done with a doctor checking on you.
Look up Dr. Jason Fung - books and videos. He's got a lot of good resources on starting the process and going from a simpler 16-8 type fast to more extended fasts, though he is careful to indicate that extended fasts should be done with a doctor checking on you.