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.
How long should you fast? Do you drink anything besides water?
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.
https://www.drberg.com/blog/the-most-important-intermittent-fasting-basics-for-beginners-must-watch-dr-berg