This is my 19th week since I began intermittent fasting. That means I have done it for over 4 months now. I started with the 16/8 method, where I fast 16 hours a day, but recently, especially since the 4th month, I have been fasting about 17 hours a day. This is because people like Dr. Mindy Pelz say that it is more effective if you fast for 17 hours.
As for how long you need to fast to activate autophagy, there are several views. Dr. Tamotsu Yoshimori, the author of Life Science, says autophagy is activated after 4 hours of fasting. Other people say it is activated after 16 hours. If it takes 16 hours to activate autophagy, I thought it was better to fast 16 and half hours or 17 hours so that you give a longer period of recycling.
Anyway, it isn’t difficult to stretch your fast to 17 hours once you get used to doing the 16/8 method. All you need to do is finish eating dinner by 7 pm, instead of 8 pm. The next day you want to eat at noon anyway since you established that rhythm. For me, it is lunch, not breakfast, so it feels strange to eat before noon. Psychologically I don’t want to eat at 11 am even it is after 16 hours and I am hungry. It is interesting to see how your mind works.
Eating dinner before 7 pm isn’t difficult at all. It naturally happens. Even when I practiced the 16/8 method and aiming to finish dinner by 8 pm, I often finished before 7 pm.
Dr. Mindy says the amount of time you fast gives you different cleaning benefits; 16 hours, 17 hours, 24 hours, 36 hours, 48 hours, and 72 hours. She recommends that you usually fast for 17 hours, and once or twice a week fast for 24 hours.
I have been fasting 17 hours on Monday, Tuesday, Thursday, and Friday. On Wednesday I have vegetable fast, which is to eat only vegetables after 17 hours of fasting and eat protein and carbs for dinner, which is about 22 hours after dinner the night before. This is equivalent to 22 hours of fasting since I don’t have much protein and carbs. Vegetables contain some of them, so it isn’t zero. This is easier than fasting for 22 hours though because I eat something for lunch and that relieves my hunger. I’ll stick to this plan for a while and eventually shift to not eating anything for lunch on Wednesday.
The Ikigai Diet: The Secret Japanese Diet to Health and Longevity