The Science of Fasting

Fasting for Ash Wednesday, not only for the religious angle but to give me extra motivation to go beyond the 18-hour mark which is where I falter. Nothing but water since dinner last night so I'm about to my "danger zone". I am drinking a LOT of water, so get out of my way.

How do you do with caffeine? I've found that caffeine helps to curb my appetite when I've wanted to do longer fasts.