I ended up running the extended fast experiment. When it comes to the human body, I care very little for all the scientific studies, except as a jumping off point, because there is so much individual variation that I've found the n=1 experiment is the only one that should concern me. Is fasting good? Bad? Screw it, I gave it a try. My goal was four days, or 96 hours.
Going in, I expected something like this: day 1, easy, due to using the warrior diet a lot, and having accidentally hit 24 hours with no problem in the past. Day 2, brutal adjustment, lots of hunger. Day 3, some hunger, but settled from day 2. Day 4, worse than day 3 and would get progressively harder from there on out.
The results were actually very surprising and interesting. First, some background on fasting. I have read that the ancient Greek Hippocratic doctors like to fast just about everyone, and they believed in something called the "healing crisis." Upon fasting 4-7 days, whatever plagued you (hippies would call them toxins, the Greeks would have just considered it the underlying illness, we can assume something like undischarged waste accumulations) would come to the surface in the form of a short, pronounced illness, an hour of darkness so to speak, then leave the body.
My experience more or less reflected that. Day 1 was a cakewalk. Day 2 was WAY easier than I thought. I figured it would be the worst day, but the fact that I didn't expect food seemed to kill any hunger pangs. I truly had no hunger, though at one time I thought of eating out of boredom, then realized I wasn't hungry, just bored. I was also extremely productive since I didn't need to acquire food, cook it, and eat it, and because I was staving off boredom instead of hunger.
Day 3 is where some symptoms materialized. I never get sick, but I came down with an alternately congested/runny sinus cavity, which just doesn't happen unless I eat like utter crap for days on end. I've heard of people trying ketosis and getting the "carb flu," so maybe this was a reflection of that experience. I never had it on the WD. Due to walking around a lot in the heat, I had slightly low energy, improving upon shade and air conditioning. Still no real hunger. At this point I began to wonder what hunger actually was, realizing that if three days without food didn't elicit it, perhaps I've never actually been hungry in all my life, and what I was feeling was either psychological (an expectation of food, a desire for endorphins after a good meal, etc) or just blood sugar fluctuations from constantly eating. It was truly shocking how not-hungry I was.
Day 4 was easily the worst day, but not because of hunger. The sinus issues were really annoying, and they peaked on day 4. It was also a Monday, so I had to go to work, which meant lots of walking in the heat on both my commute and at work, so my energy was very low. I decided this would be a good day to fill out my performance self-review, and I was very happy with the brevity and honesty I used due to not caring enough to make an effort. It was Office Spacey. By the evening, I knew I was allowed to eat that night, but decided I might as well go into day 5. I was pretty unhappy from the energy level and snot, but actually did not feel like eating anything. I resolved to eat the next day before my boxing lesson, because I thought I needed the energy to get through that. Worst day due to mucus discharge and heat, but still a shocking lack of hunger. I even walked through a grocery store and bought food for the next day without any of the usual deaire to eat everything on the shelves and the hot bars that I would experience on a normal day.
Day 5 was the dawn after the darkness. I thought the night before that it would be such a struggle, but I woke up with my sinuses much better and feeling full levels of energy. Blew my nose, expelled gobs and gobs of the brightest yellow mucus I've seen, and I felt like I could continue fasting indefinitely. Day 5 was the easiest day since day 2. I ate around noon--just a light salad--because I didn't want to risk poor energy at my boxing lesson, but I wasn't even that excited to eat, had to work to get it down, and afterward kind of wished I hadn't. Luckily I knew not to gorge, but even the salad seemed to make me feel stuffed (this from a person who has many times eaten 5 lbs of food in a day, literally). Had perfect energy all day, and ate a very light supper of three chicken legs (have eaten 8-12 as a standard serving in the past). This felt like plenty.
Fast officially ended at 109 hours.
My sinuses have not completely cleared up, but I think it's due to me walking around a lot as everything here is blooming and getting a bit of allergies. They are much better since day 5, though. I learned that I have no idea what hunger feels like, and I did feel like the fast and the period of catabolism did some really nice things for me once I made it over the hump. I'll probably make a periodic habit of it, 2-3 times per year, and next time I aim to go the full seven days.
Forgot to mention, but I drank tons of water, and allowed myself one coffee in the AM, one tea in the afternoon, and one tea at night. After day 2 I didn't even drink the teas, just the coffee. Also added a bit of salt to my water occasionally for hydration purposes.
Going forward, it seems like it will be a lot easier to resist temptations of crappy, convenient food because I know for a fact I can wait a very long time. I also plan to eat less volume overall. I will never again complain that I'm hungry, as I have no idea what kind of time period it would take to actually feel hunger, but I know that it's more than 109 hours.