Stay busy, distract yourself with interesting things. I have done 3-4 days water fast a few times out of curiosity. In my case, the hunger cravings diminshed a

Stay busy, distract yourself with interesting things. I have done 3-4 days water fast a few times out of curiosity. In my case, the hunger cravings diminshed after 48 hours or so. However, I've never feel better, worse, or different from the experience. No extra energy, no extra ability to focus, no changes in sleep, no excessive fatigue, etc. Other than the hunger, I felt normal. I am convinced that fasting is a fad and may have placebo effect if you think it will. Addition: I have used a 48-72 hour fast as a precursor to a longer-term low carb/keto diet (for weight loss). The fast will get the excess sugar out of your system and you'll be able to get into ketosis quickly.