I experimented with fasting almost a year ago now, from OMAD all the way to 6 day fasts. My only motivation was to lose weight and I figured working from home was the best chance I'd have to actually go through with it. I lost around 35kg and I'm finally at a healthy weight for the first time in my life. Of course I'm very happy with the results, but I didn't experience any benefits people mention concerning mental clarity or more energy. To be fair I also didn't feel much worse than usual after a few weeks of starting.

What did give me more mental clarity and energy was eating well and exercising regularly, something that I had to come to terms with when transitioning back to a more traditional diet else I'd just end up putting the weight back on.