Anecdata: I've tried fasting of various kinds over the last few years, both IF (18:6) and 5-day fasts. Personally, I found great cognitive benefits from fasting

Anecdata: I've tried fasting of various kinds over the last few years, both IF (18:6) and 5-day fasts. Personally, I found great cognitive benefits from fasting, starting day 3 or 4 in the 5-day fast. That said, I found the most benefit from: 1. Maintaining a very low-carb diet (~20 net carbs spread out through the day, mostly from lemons) which I have sustained for a year so far. I occasionally cheat but not often as it takes me about 8 days to get back into ketosis after each cheat and never feels worth it after the fact 2. Exercising (weight lifting and cardio) 3 times per week 3. _Never_ eating anything with 'added sweetener', so pretty much no desserts of any kind. This includes 'neutral' sweeteners with no calories (e.g., monk fruit). It has been almost 2 years since I have eaten any kind of dessert and I very rarely miss them at this point Doing the above, I feel amazing almost every day. I have no known bodily ailments, never get sick, have sustained energy levels all day, every day, and am my ideal weight with little fluctuation. The hardest part of sticking to my rules has been maneuvering through incessant social expectations and demands to eat particular foods, like breads, desserts, etc.