To shift one's feeding window for intermittent fasting, transition over 1 to 10 days by adjusting the window about an hour each day.

“winnowing down that feeding window about an hour or so per day is going to allow the hormone systems of your body, including leptin the hypocretin orexin system, which are systems within the body, that signal to the brain, that food is about to come allowing those systems to adjust so that you're not overwhelmingly hungry, irritable, and you're not throwing your whole hormone system out of whack.”

“one needs to provide a transition period in order for that to happen, you should allow yourself a transition period of anywhere from one week to 10 days in which you shift your feeding window by about an hour each day or so.”

“I do want to remind you that taking a period of 3 to seven or ideally 10 days to transition into it, not just going flipping from eating to three meals a day that span from 6:00 a.m. to 10 p.m. and suddenly going to an 8 hour feeding window, but rather winnowing down that feeding window about an hour or so per day is going to allow the hormone systems of your body, including leptin, the hypocritein system, which are systems within the body that signal to the brain that food is about to come. Allowing those systems to adjust so that you're not overwhelmingly hungry, irritable, and you're not throwing your whole hormone system out of whack.”