Five Day Fast: What I Learned By Not Eating For Five Days

The morning of November 11, I decided I wanted to try a fast. After eating supper at 5 pm that evening I never consumed anything but water until November 16, five days later.

If you’re like most people, who heard I was doing this you’re probably wondering why. I don’t have a great explanation.

That morning I drove to Tim Horton’s, walked in, waited in a line for five minutes and walked up to the till only to discover I had forgotten my wallet. Driving home, doomed to the fate of homemade coffee, I was listening to something about fasting leading to improved cognitive function. Maybe this would be worth trying? I soon discovered there are plenty other benefits of extended fasting.

Most of the benefits of fasting result from a process called autophagy. This process helps the body to destroy bad cell matter. In practical terms, autophagy prevents cancer development, increases lifespan, slows neurodegeneration and even leads to the production of new brain cells. Perhaps with these additional brain cells I would be coming home from Tim Horton’s with two coffees and a timbit for our dog instead of crazy ideas like not eating for five days.

Fasting causes your body to go into a state known as ketosis. This means that your brain is burning off fat to run because there is no glucose (created from carbohydrates) available. So yes, there is also a fat loss benefit. I had been interested in ketogenic diets lately, and this would make a good jumping off point for trying one. (Note: it usually only takes 1-3 days of fasting to get into ketosis, or it’s possible to attain it without fasting).

Fasting is also shown to improve our insulin sensitivity, making you more resilient when you consume junk food.

Ok, so there are probably some dangers that come with doing a fast of this length so maybe talk to a doctor or something if you are thinking of trying this. I was curious as to whether I would experience any of these benefits; I couldn’t imagine feeling great after not eating for more than a couple of days! But I did.

I can’t believe how good I felt on days four and five. It was the sharpest I’ve felt possibly ever. I was so focused. I would start doing something and time would just fly by as I accomplished the task. Tasks just flowed seamlessly into each other. The only downside to this is sometimes it was hard to start a task because my brain felt so focused on not doing anything.

Over the first few days I encountered a few negative effects:

– Minor headaches. I rarely got headaches. When I did, they lasted only five to ten minutes. I assume they were the result of dehydration.
– Dizziness. If I moved to fast, it felt like I might faint.
– When I walked too much, my legs were sore for the rest of the day.
– Colder. Our office is usually cool, but I felt colder than normal.

I imagine you have to pay attention to this stuff. If I had ended up fainting or had a headache that lasted more than a day, I probably would have interpreted it as my bodies way of telling me to stop and listened to it.

As you can imagine, social situations also got a little bit trickier.

– Saturday night we did dinner and a movie with my girlfriend and her family… I drank ice water at dinner and hot water at the movie.
– My work has too much free food. I had to pass up on a catered breakfast and lunch. As well as a fridge full of free food accessible just outside my office.

No coffee was hard at work. I like to be sipping on something while I work. Since I couldn’t drink coffee, and I was cold, my girlfriend suggested drinking hot water. This helped a lot. I stayed hydrated and warm! I’m still drinking hot water at work instead of coffee since I find I don’t need the caffeine; I just need something hot to drink.

My relationship with food changed. Before when I felt a craving for food I would usually give in. Now, I realize that most of the time food cravings and hunger are just internal voices that I don’t necessarily have to obey.

When I began the fast I was worried I would wither away into nothing. Ok, maybe not nothing, but I didn’t want to lose a lot of mass. When I began, I weighed 173 lbs, and when I finished, I had only dropped to 165 lbs. I lost most of the weight in the first three days. However, as I write this a few days later, I’m still at 167 lbs. So I would guess a lot of it was fat loss.

I ended my fast Monday evening, 121 hours after I began it. This brings up the topic of refeeding or reintroducing food to your body. If you aren’t careful, you could encounter something called refeeding syndrome where you spike your insulin so much that you go into shock and possibly die. So maybe save that tub of Oreo ice cream for another meal. My first meal was Athletic Greens and an avocado and mixed nuts then some asparagus. I avoided meat, but I don’t know if it was necessary. Any small piece of protein and a few vegetables and you’ll probably be fine. Probably best to avoid high carb foods (including fruit) because of their higher glycemic indexes.

First meal in five days!

Honestly, I’m still blown away by how positive of an experience this was. The positives far outweighed the few downsides. I loved how sharp my mind was. I am more confident in my willpower, and it’s cool to think I did something that I had never done in my entire life. I plan on trying something like this again in a few months; maybe you’ll join me?

If you have any questions, you can always ask me via email or twitter or leave a comment below.

6 thoughts on “Five Day Fast: What I Learned By Not Eating For Five Days

  1. Hmmmmm interesting Karson. I would have thought fasting would make me extremely grouchy and unable to concentrate! I feel like giving it a try now for curiosity sake :) ps. memories of math class still make me laugh from university, hope all is well!

    1. Thanks Meagan. The concentration part is so unexpected because at times it felt like I wouldn’t be able to focus on anything then I just magically did.

      Oh math, I still don’t know how I passed that class haha

  2. That it super interesting that it was such a positive experience. I would have thought you would have gotten more sluggish and it would have been tougher at the end. I’m curious to try it! Will have to give it a go sometime!

    1. Day three was probably the trickiest but four and five were just unreal, I felt like I could have went another day or two at that point. It’s a fun challenge in willpower that’s for sure!

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