The one you can stick with long term to meet your weight loss goals. If that is a 16 hour fast, 23 ( ie omad ), ADF or multi fasts then do that. Some people do well on the multi day fasts while others may refeed too much or return to the same habits gaining it back. So just experiment and figure out what works best for you.
The one that you can sustain indefinitely, and that is going to be different for each person. In many ways this sub and various FB groups on the subject are a revolving door. People do good for awhile and then they disappear. They pack on more pounds and then come back 6 months or a year later to try again.
This happens because they failed the sustainability test. Fasting is really no different than any other yo-yo or fad diet unless it can be seamlessly integrated into your life. Many people here favor extreme measures, almost as if they are trying to punish themselves for their past sins. This is not a healthy way to go about things.
16:8 daily fasting is sustainable for me, which I’ve been doing for a few years. If I fast for longer, I just pile on the pounds when I can eat.
I exercise 5-6 times a week and prolonged fasts or low restriction does not work for me. I simply can’t function on limited calories. My maintenance calories are 1,700 and I create a calorie deficit through exercise.
Well, from my personal experience, I feel OMAD in combination with bodyweight exercises while fasted is an effective weight loss strategy, I have lost 15 kgs and have been able to maintain low body fat percentage and muscle for over a year now.