What to Expect From a 3 Day Fast If You’ve Never Fasted Before

My dinner during my three day fastMy typical dinner during my 3 day fast. You get the point by now.

It Was the Shit That Convinced Me

Ridiculous as this may sound, what motivated me to try a 3 day fast was hearing about the shit.

I had yet to read a couple books about how extended fasting would help me live longer and healthier (see Resources below), so I’d never even considered not eating for longer than 24 hours. It was a story my sister’s boyfriend told me about his own experience that made me eager to try.

He told me that at some point towards the end of his 3 day fast, he went to the toilet and all sorts of crazy shit (literally) came out. It was kind of like cleaning out your garage for the first time in 30 years, he said.

My garage could use some cleaning. I was sold.

So with my girlfriend Kim away traveling and thus unable to nag me about how I was starving myself or tempt me with delicious food, I decided to give a 3 day fast a go.

Man was it a mind-blowing experience!

3 Day Fast, Day 0

The Last Meal

To celebrate (mourn?), I made a delicious and humongous Sunday night dinner, capped off with some Toblerone and a cocktail to celebrate. Then I began my 3 day fast. No more cooking, dishes, or chewing for 72 hours. Just water, tea, and black coffee.

I went to sleep feeling like a marathoner about to start his first race.

3 Day Fast, Day 1

my breakfast during my 3 day fast
My daily breakfast during my 3 day fast. Coffee and air.

Setting Off on a Voyage of Self-Discovery

My first day was kind of like that of an early explorer setting out in search of the New World. I wasn’t entering new territory—I’d done 24 hour fasts before—but this time it felt different. This time I wasn’t turning back. I felt anxious and nervous.

Monday morning started as usual with my regular routine of heavy lifting at the gym (and a new personal best!) followed by a bunch of online computer work.

Then things got unusual.

Something’s Missing

Normally I’d have a big early afternoon meal, but this time… nothing. Just black coffee.

What felt stranger than not eating was not having my ritual midday lunch break. Rather than catch up on sports and social media while slurping down a smoothie and some eggs, I just kept on working. Who’d have thought fasting could lead to more productivity!?


My girlfriend Kim, who was supposed to be away until Wednesday, surprised me by coming home early. And since I hadn’t told her of my 3 day fast plan, she had brought some fresh salmon for dinner. Damn.

Surprisingly though, even as I watched and smelled her cook then eat delicious-looking meal with envy, I didn’t feel hungry. I felt good.

3 Day Fast, Day 2

Typical lunch during my 3 day fast
My daily lunch during my 3 day fast. Water and air. Sometimes tea too.

Uncharted Territory

What a weird feeling it is to wake up after a day of zero calories for the first time in my life. I could joke that I literally felt empty inside, but it didn’t. I felt great. My sleep tracking app even said my sleep quality was 100%.

Feeling Electric

From the morning of day 2 to the end of my 3 day fast, my mind felt electric. As if I was high on Adderall,  I hadn’t felt more focused in ages.

This, I found out afterwards when I read some books on the physiology of fasting, is entirely to be expected. My brain was running on cleaner fuel than it was used to and my entire body was benefitting from hormonal boosts.

I worked all morning in a hyper-focused zone. Then when my eyes started to twitch from too much staring at a screen, I walked to the nearby beach to unwind. I tried meditating for 20 minutes and… holy hell! I swear to God at a certain point I felt high. Amazing.

The First Negative Experience

Unlike on Day 1, I definitely didn’t make any personal bests in my Day 2 workout. I felt like I did the day I tried working out after taking the bus from Lima to Huaraz in Peru (an elevation gain of 3000 meters or 10,000 feet).

My body felt strong, but it didn’t have the endurance it normally did. After one or two lifts my strength evaporated, and at times I was lightheaded to the point of dizziness.

I was glad to have gotten some exercise, but it was certainly the first negative effect I felt on my 3 day fast.

An Unusual Day

Again, not having my ritual meal brakes for lunch and dinner was a trip. Honestly, I missed the ritual even more than the food itself. I didn’t know what to do with myself. It was like double daylight saving time: normally I’m ready for bed at around 11 p.m, but this time I was ready by 9. My brain wouldn’t stop buzzing, though, so I ended up reading in bed for hours.

Oh yeah, and most importantly (and disappointingly): no shit. No number 2 at all on day 2 of my 3 day fast.

3 Day Fast, Day 3

My dinner during my three day fast
My typical dinner during my 3 day fast. At least it was inexpensive…

What the Hell?

Normally I wake up around 7:15 a.m. Today? At 5 a.m I was up and ready to go. My sleep app told me I had 90% sleep quality.

I still wasn’t hungry and mind felt sharp. So too did my hearing and smelling, which felt strangely super powered. My body though, felt lethargic.

The weirdest feeling though? My mouth.

My mouth was like the factory of a company that had just gone bankrupt. It’s all spic and span and ready to go, but empty. My breath felt strangely fresh and empty and my jaw tight from lack of use. Indeed, the night before I wondered to myself, “Do I actually need to brush and floss?”

Caving In

Do you remember how weird your teeth felt after getting your braces off? Or your arm or leg when the doctor removed your cast?

That’s how my stomach felt the last morning of my 3 day fast. It had deflated overnight and felt completely foreign to me. I couldn’t stop touching it with my hand. Normally I can do that stupid trick of sticking out my belly like I’m pregnant, but I couldn’t anymore.

It didn’t hurt or anything. It just felt tighter than normal, in a good way.

Pushing the Limit

Feeling mentally sharp but physically lethargic, I nonetheless went to the gym to see just how much juice my body had left.

Answer: Only a few drops.

I managed about 80% of what I do when nourished. Strangely, I even felt sick to my stomach. When I shot some hoops after to cool down, I could barely make a free throw.

My weight, which normally hovers around 197 lbs, was down to 189.

3 day fast dessert
Dessert during my 3 day fast. Not much to look forward to.

The End

That afternoon I still wasn’t hungry, but I couldn’t help but daydream from time to time about my upcoming evening meal. I had grand visions of a gluttonous feast where I’d recover all the calories I’d missed out on at once.

Those visions were not realized. I ate half as much as I thought I would and the food didn’t even taste any better.

Immediately after eating, I had my first bowel movement since Day 1. Excitedly I went to the toilet. But it wasn’t a “garage cleaning” of crazy shit like I hoped. Just a couple tiny turds.

Despite the anticlimactic end, my 3 day fast was overall a mind-blowing experience that I will definitely be doing again. Maybe even longer next time!

Try Your Own 3 Day Fast!

If you want to try yourself, I highly recommend you prepare yourself by doing some 16-24 hour fasts first. They are good for you in their own right, and will help wean you off the addiction of non-stop snacking.

Once fasting for a day is no longer a big deal for you, you’re ready to take the plunge and try a 3 day fast of your own. If your experience ends up anything like mine, you’ll never forget it.

Must-Read Books on Fasting

In preparation for you fast, I also recommend you read the following two books. They explain what happens to your body when you fast, why it’s worth trying, and how to make it less difficult. Both books also contain some motivating examples that might help you power through your own fast.

Though both written by doctors, anyone can read and understand them easily. Even me.

The Complete Guide to Fasting, by Jason Fung

I wish I had read this book before I did this fast.

Not only does Fung explain exactly how and why fasting works, he provides helpful tips to make fasting easier. For example, he writes that if I had had some bone broth I might not have felt so light headed.

I followed this advice on subsequent multiple-day fasts and found it made all the difference.

The Longevity Diet, by Valter Longo 

This book isn’t only about fasting, but about Longo’s research into what diet is best for a long and healthy life.

I was quite surprised by his findings, including that ketogenic diets reduce lifespan more than any other, and that diets that are much heavier in carbohydrates than so many fads these days recommend actually promote longevity.

The sections on fasting are entirely consistent with what Jason Fung writes in his book. Unlike Fung, though, Longo has found his patients didn’t have the willpower to fast for long periods, so he developed a fasting-mimicking diet that allows people to eat something while still getting about the same benefits.

All the Best With Your Own Fast!

“Good luck” isn’t the right thing to say, since there’s no luck involved in not eating. I should probably say, “All the best!”

A three day fast really is all the best for your health. It’s definitely daunting for first-timers, but it’s worth it in the long run and you won’t regret it. Hopefully, this post will help you prepare mentally and understand what to expect.

If you have any questions or have different experiences on your own fast, please share with all of us in the comments. 

And, once again, all the best!

Chris is a guy from Canada. He particularly likes sports, nachos, and Kim, who is his accomplice in running The Unconventional Route.

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