I tried single day (don't eat anything in a single waking period, not strict 24-hours—over 24 hours, in fact) fasting a few times a couple years back. I don't u

I tried single day (don't eat anything in a single waking period, not strict 24-hours—over 24 hours, in fact) fasting a few times a couple years back. I don't usually eat breakfast anyway (rarely feel hungry in the morning), but ~1hr after I usually eat lunch I'd feel fairly bad, and by 3pm or so I'd feel quite weak and mentally sluggish. I still plan to try a 72 hour fast at some point, but I'm expecting it to be very unpleasant based on those experiences.