My 3-Day Water Fast Journal


Stemming from the days of maintaining and making specific weights for karate competitions, I’ve always had an interest is biohacking. I do 24-hour water fasts with some regularity, but the furthest I’ve stretched it is approximately 36 hours. I never thought I had a reason to go further. Well, what better reason is there than for learning?

If you’re curious why I’d want to starve myself for three days, there are a host of health benefits related to prolonged fasting including stem cell reproduction and the cleaning out of older aged cells. Here are some podcasts if you’re interested:

I’ll be chronicling the process here. Not to look past the current obstacle but my real goal is eventually a 5-day fast. I included a Day Zero below to describe my planned process and what’s happening leading up to the fast. I’ll document my status each morning and night along with bulleted updates throughout the day.

Day Zero

From doing previous water fasts I know that headaches are the biggest obstacle for me. They’re caused from a lack of caffeine (I’m a steady coffee drinker) and from flushing out electrolytes. As a small compromise I’ll allow myself a single cup of coffee each day as well as Code Age’s Keto Electrolyte Capsules. The capsules were readily available; I’ve taken them in the past and enjoyed the results. I normally put a tablespoon of MCT oil into my coffee, but I’m going to try to go without for the duration of the fast.

I ate my final meal before the fast at 6:45 PM. A set of 8 pan-fried chicken wings. Water consumption was normal for the day. Excited to get started!

Day One

The ramp up day. This is familiar territory for me as I do 24-hour fasts about once a month. I’m expecting some keto-flu symptoms since I wasn’t very disciplined the days before the fast and ate my share of carbs. There are many symptoms, but for me it’s going to mean headaches, maybe an upset stomach, and bouts of hunger.

  • 5:15 AM — Slept for a normal seven hours. Felt hungrier than normal, but I’m attributing that to the mental strain knowing I won’t be eating. Went through my normal morning routine doing three sets of 3 standing ab wheels and 10 reverse hypers with no issue. Holding out until midday for my coffee may be a struggle.
  • 11:00 AM — Just poured my cup of coffee for the day! One thing that is difficult for me water-fasting is that I don’t particularly like water and prefer to mix up the flavors of what I drink throughout the day. Took an electrolyte capsule with it. Easy going so far except feeling a bit cold. Stomach is calling, but I won’t be answering.
  • 3:00 PM — Hunger has subsided almost completely and energy levels are pretty good. It’s nice hitting the home stretch of the day without the post-lunch fog. Drank about half a gallon of water so far rotating between room temp, iced, and hot.
  • 5:00 PM — I think I just peed for the 9th time today. The hunger is gone but I have a slight headache. Feels similar to eye strain or a migraine, taking a second electrolyte capsule. Getting ready to finish up my day and work out tonight.
  • 9:15 PM — Just finished a 45-minute sparring class and feel great. Driving home I started to get a dull headache but after drinking water it went away.

Day one is in the books. I noticed a bit more build-up when brushing my teeth, which I’ll attribute to being a bit dryer. Hoping I get good rest tonight! I’m comfortable with the 24-hour fasts. Tomorrow is the crucial day for me as I’ve quit at around 36–40 hour multiple times in the past. This blog is helping keep me honest and treating this as a learning experience instead of a “need to prove myself” mindset is keeping my mentality more positive.

Day Two

I’m extremely curious about fasting’s ability to promote autophagy, which is effectively the process of cells replacing their older more worn down parts. Think of upgrading a PC’s graphics card or going through a set of paints and replacing the ones that are dried out. From what I’ve read (here and here), autophagy is critical to longevity and anti-aging (here too but it was too sciencey for me). Sadly there’s no easy way for me to measure this so I’ll have to take a leap of faith for now.

  • 6:45 AM — Slept for almost eight hours. Feel rested but a little sluggish to get up. Lips and mouth are oddly dry and I feel more sore than I thought I would from yesterday’s exercise. Not feeling hungry, but my stomach does have a bit of a tug as if to remind me it’s there and hasn’t been paid attention to.
  • 9:30 AM — Started to get a headache when I got into the office, but after 64 oz. of water and an electrolyte cap I’m feeling better. Mouth is a bit dry too which makes speaking during calls difficult.
  • 12:45 PM — Half-way through my fast! Just brewed my one cup of coffee and honestly I feel better than I have throughout the entire fast thus far. No hunger pains, headache and neck stiffness has subsided and I’m most importantly optimistic. I’m even thinking “what if” for day four. Unfortunately I have a hiking trip Saturday and there’s no way I’m doing that in a prolonged fasted state.
  • 6:45 PM — Completely on auto-pilot as I round hour 48. Haven’t had any hunger pains or headaches in the last 12 hours. As I sit next to a slice of pizza, smelling food triggers a desire to eat, but not through hunger. I simply miss the act of eating. Hoping the idle time of the evening doesn’t get my mind wandering on food too much. The trick through all of this has been to stay busy.
  • 9:45 PM — Getting through the evening wasn’t too bad, but it wasn’t a walk in the park either. Sitting on the couch reading and relaxing, thoughts of food started to creep into my mind and with those thoughts came cravings. I miss the act of eating. It’s not about being nutritious or feeling sustained, it’s simply the enjoyment of choosing and experiencing tasty foods.
  • 10:45 PM — I decided to check my glucose and ketone levels even though I haven’t been very good about my diet the past few weeks. I expected to be in a mild state of ketosis but my numbers were startling. Using a Precision Xtra blood monitor I recorded a ketone reading of 2.7 mmol/L and a glucose reading of 78 mg/dL giving me a glucose-ketone index (KGI) of 1.6, which is excellent. Go ketosis!

I’m amazed at the intelligence of the human body. Reflecting on the past two days, my body has hit cue after cue adapting seamlessly. Starting from the morning of Day 1, the mental pressure to sustain myself kicked in. With each passing meal time I felt spikes in my hunger that was compounded with headaches when I did not listen. Then, just like clockwork, my body came to grips with the reality that I was not going to feed it and the fog, discomfort, and pangs subsided as I switched to being fueled by reserves. I feel like I’ve had my fill of calories for the day and it may be psychological but overall inflammation, soreness, and bloat seems to be decreasing.

Day Three

I did not sleep well last night. After waking up around 1:30 for a bathroom break, I tossed and turned for about an hour trying to fall back asleep. I eventually did, but it was not deep. I woke up again at 5:15 and stayed in bed for 45 minutes not feeling rested. Now that I’ve gotten up I feel better, but the feelings of hunger definitely affected my ability to rest.

  • 7:00 AM — Leaving for the office now. I feel better having been up for a bit, washing my face and moving around. My morning exercises were harder than normal. I don’t know if it’s from lack of sleep or lack of food, but I’m thinking the former.
  • 8:30 AM — Having my cup of coffee early today. Partly because I feel really cold, but also I’ll be busy around mid-day when I normally had my coffee. My calves are starting to cramp periodically, felt it while I was sleeping.
  • 9:45 AM — Just did another blood reading. GKI of 1.26 (68 mg/dL and 3.0 mmol/L). These are some of the best numbers I’ve ever had, crazy that I’m this deep this fast in ketosis. Might have found a new strategy for course-correcting when I fall off the horse.
  • 1:30 PM — Physically doing great, but having office lunch this close to the end of my fast is no fun… I prepared a plate for later this evening!
  • 5:00 PM — Holy shit, my ketone levels are through the roof! GKI of 0.85 (58 mg/dL and 3.8 mmol/L). Easily the best numbers I’ve ever had, and the first time my index score has been below 1.0. I’m practically salivating at the thought of food right now, but I’m not feeling hunger pains or anything else beyond just missing the act of eating.
  • 6:45 PM — MISSION COMPLETE! I gotta say even now I’m not feeling hunger, but I’m definitely ready to eat. This has been a great experience. I’m full of confidence and just as excited to try another fast as I am to eat.

Fast Debrief (Pun Intended)

I woke up pretty sluggish today. Yesterday I broke my fast with a small plate of rotisserie chicken, mac ‘n cheese, and a small corn bread. I then followed up shortly after with hot pot, which is basically boiled meat and fish in seasoned broth. Probably a bit heavier than I should have gone, but we had company over.

In the aftermath of this 3-day fast I reflect back and realize I learned a lot about myself.

  • I have a dependency on caffeine, the cup of coffee each day was extremely helpful
  • I breezed through this fast with relative ease and I strongly attribute that to this journal holding myself accountable.
  • Prolonged fasting is definitely going to be my way of initiating a keto-cycle
  • Attempting Completing a 5-day fast is on my near-term to-do list
  • Your body is incredible at adapting to its environment
  • Your body is a really fun laboratory for experimentation and learning
  • I want to find ways to improve my sleep while fasting
  • It’s not a question of if you can do it, it’s a question of if you want to do it

I invite anybody to try out at least a 24–48 hour fast. Although honestly if you don’t go beyond the 48 I feel like you’re getting through the painful parts and quitting right before the real beneficial stuff. Happy Hacking!

Originally published at on August 21, 2018.



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