I don't really like either the Warrior Diet or alternate day fasting.
There is no need for an undereating phase within a day, except for cases where the person really cannot handle fasting. Then, the person should shorten the fasting window, consume caffeine, or abandon intermittent fasting.
One of the reasons daily IF works so well is because our bodies adjust to our eating patterns, so we usu. don't get very hungry during our fasting windows. Unusual stressors can throw that out of wack though. Also, the longer we fast the greater the percentage of our energy expenditure comes from amino acids, which is why a 14-16 hour fasting window is ideal.
Hans, if you haven't already, you should go and read all the articles over at www.leangains.com