Just how do you do intermittent fasting? Most IF'ers consume for 8 hours a day, not eating the various other 16 hrs. The length of time do you have to fast for intermittent fasting? You can start with a 12-hour quick and function your way to 16 hours. A lot of IFer's consume from 10-6, 11-7, or 12-8. It doesn't matter what eating home window you ch