I did fast through the superbowl and that was terrible! I am at the end of day 5 on an extended water fast. The longest I have done before was 7 and this time I really wanted to go longer, but my energy level is so low I don't think I can do it. I hear so many people say that after your body adjusts to running on ketone bodies that you feel fine, but that hasn't been the case for me yet. Why do you think you should eat protein on im-fasting days?