MM recommends non-consecutive fast days. Back to back is hard. I’m not surprised you’re exhausted. Maybe try non-consecutive fast days next time? Also… it does get easier. Try to keep your caffeine levels the same as usual, and consider a salty broth to replace some of the salt you don’t get because you are eating less. I find a miso soup perks me right up!

I never did consecutive days; I’ve only done Monday and Thursday since I began in April of this year. I did find on my first two fast days that I was tired and would get cold easily, and the first day I also had a headache, but subsequently it got easier and now I do not have any of those symptoms on my fast days.