I have had similar experiences; I did a lot of water fasting, lost a lot of weight (50lbs over 18mos), and then after all that fasting the sugary things just were not as appealing.

On top of that, I find it easier to go into water fasting if I've been in ketosis for a bit, which is difficult in itself.

But for that, I've found it helpful to remove other dietary restrictions; I don't typically eat dairy, and the stuff I do like to eat in keto is often much more expensive than the beans and rice / peanuts/ fruit that are the staples of my diet when I'm not trying to force ketosis or fast. Eating nicer food (usually meats, lots of eggs, dairy) makes being that process easier.

Yep. I had an unbelievable sweet tooth since I was a teenager. I was having 10+ cans of coke per day on top of multiple king size candy bars. When I was ~30 I did a 36 hour fast and afterwards has 0 desire to have anything sweet for the very first time in my adult life.

It came back a few weeks later, but over a few years I tried fasting again and it would go away every single time. Now I try to avoid sweets as much as I can but when old habits creep back in I just have a fast and it goes away.

I don't really fast for any reason other than knowing it will take the sweet tooth away—and generally make me want to eat healthier.

I love water fasting and do it often. But it also is highly dependent on weight. If you're a lower weight already, it can be really hard to do a 3 day water fast. I used to be able to do them pretty easy, but after cutting weight it's become much harder. I do modified fasts where I take protein and fat both.