During the 25-hour fast of Yom Kippur, many people suffer from dehydration, low sugar levels, and lack of caffeine. It is much easier to persevere and achieve success if you prepare well in advance.
Wean Yourself From Caffeine:
The one thing regular coffee drinkers miss the most during Yom Kippur is coffee. They miss caffeine even more than water.
Coffee consumers should taper off their caffeine consumption during the week before Yom Kippur.
Avoid Dehydrating Foods: