Peter Attia has quite a lot of content on evidence for fasting techniques if you like technical podcasts. I’ve done intermittent fasting as a prime to lead up to 72 hour fasts. I find meditation 10 minutes a day to be a great way to do this stuff. I also find that episodic intermittent fasting helps me get control of bad eating habits when they creep back in. Evidence is that intermittent fasting doesn’t have any benefit for weight loss compared to other diets. However, some people do really well and find it helps them lose weight. It’s a nuanced issue. If I do it I like to eat between the hours of 10 am and 6 pm but there is no one best way. The meditation helps you develop calmness about not eating when you first wake. Here is Peter’s new book that helps cover stuff like this too.