I’m Type I and the longest I’ve done is 48 hours, my regular program is three times a week 24 hour fasting and IF the rest of the time. If my blood sugar goes below 70 I have a shot of apple juice. Your blood sugar won’t keep dropping and dropping ,after you get beyond glycosis your blood sugar will (generally) stop dropping and stabilize. My problem is the initial blood sugar jumps whilst in glycosis, but once that’s done I’ll hang somewhere between 80-150. Best of luck.