Literally couple of hours of bad eating is enough for undoing weeks of fasting.
This is not a quick fix. It’s a life style change.
That’s not been my experience at all. I’ve lost 30 pounds doing this over the last year. Even if I did pig out one day 2 days later my weight was back to before. It’s only through continuous poor eating that any came back.
I was 50.6kg 2 weeks ago. I had 6 cheat days (ate twice more Calories everyday). I gained weight up to 56kg. I want to do water fasting, but I keep failing and end up eating something everyday. But, with experience & practice, I only eat in calorie deficit. And today, my weight was 53.5kg. (Very professional and the original natural way.)