Originally published here on July 22, 2021

Motivations for and Learnings from Consuming 0 Calories for 168 hours

Last month, I completed my 3rd 7-day fast in the last 4 years. Just good ol’ water, tea, and a few magnesium tablets for 168 hours. I want to shed light on why anyone would want to do this voluntarily by sharing my experience, what I learned, and some tips for the curious.

Before I get started, I want to disclaim that, as always, you should do your own research before throwing yourself into unknown territory. Certain people might not be fit to fast and should consult their doctor before doing so.

After I quit my job last December, I wanted to deliberately take time to learn about myself: explore new hobbies, routines and also push myself. I knew this would be a unique time to experiment and hopefully also set the foundation for new healthy habits. I’ve dabbled in fitness, breathwork, and mindfulness practices, meandered and pondered while strolling hundreds of kilometers around Berlin, but also experimented with my diet.

Recently, I’ve caught myself eating less consciously and sometimes even to seemingly no end. Shortly after returning from a recent vacation, I left the house with my shopping bag to head to the grocery store. I was considering experimenting a few weeks with the intermittent fasting routine “One-Meal-A-Day” (it’s exactly what it sounds like) to challenge myself and eat more consciously. Somewhere on the way to the store, the thought “why not go all the way and fast completely?” entered my mind. So I took a quick 2hr detour listening to various podcasts on fasting, snatched a celebratory burrito, enjoyed every bite of it, and set my fasting timer to 168 hours. Expert preparation, I’m aware. I obviously never made it to the grocery store.

Why bother?

Fasting has been practiced for thousands of years, often for religious reasons, and with some mindfulness and health motivations thrown in as well. I noticed my main motivation was three-fold: regaining an appreciation for food, setting and completing a personal challenge, and experiencing health benefits.

Re-appreciating food

I am aware I am speaking only for a subset of the global population, but many are living in an age of abundance, especially in regards to their diet. In large cities, food can be found at every corner, visiting (or ordering from) restaurants is an integral social experience and even supermarkets now deliver food to your apartment door in 10 minutes.

Not only is food available everywhere and at all times, but I’ve observed it to be consumed at an increasing speed and quantity. Hastily shoveling down lunch in front of laptops or devouring a frozen pizza while watching Youtube is an everyday occurrence for many. I catch myself in these moments more often than I’d like to admit.

If only for a limited time, I wanted to break this cycle to purposefully restrict my access to food in order to dramatically increase my appreciation for the delight that is fresh food. Of course (sadly), after resuming a regular eating schedule, this appreciation quickly drops to nearly pre-fasting levels. Nevertheless, I’ve observed a permanent increase in my appreciation for food after every fast.

Personal challenge + feeling of accomplishment

Like many of my friends and the people I draw inspiration from, I believe in continuously pushing my boundaries to experience myself and my capabilities more fully. I appreciate learning about how my body and mind function and enjoy the satisfaction of setting goals and accomplishing them, no matter how large or small.

The world is rich in opportunities and experiences and I find it increasingly dull to simply stick to tried methods at all times. Seemingly daunting challenges look astonishingly less daunting in hindsight. I derive confidence from realizing my body and mind are capable of much more than I would intuitively think. Fasting is therefore an opportunity to break out of set routines, embrace discomfort, and come out slightly stronger and resilient on the other side.

Health benefits

The research is still emerging, so I will not go into too much detail here. First studies promote the potential benefits of (intermittent) fasting towards heart health, obesity, diabetes, high blood pressure, learning & memory, as well as longevity (see Cell, American Journal of Medicine, Nature). Fascinating experiments in worms and mice have shown that their life expectancy could be increased by up to 28% simply through reducing their food intake and frequency!

On top of the potential long-term benefits, simply the idea of temporarily capping the intake of all ingredients entering my body to enable a “full reset” seems intuitive to me.

While the details of the processes within our bodies during fasting are still unclear, one can observe all body functions slowing down, as organs – especially the gut and digestive tract – are permitted to rest and the body excretes built-up toxins through the skin and tongue. To top it off, our cells enter a state of autophagy, which cleans out dead cells and helps with rebuilding new ones. The thought alone of positively influencing my body at a cellular level motivates me.

What does it feel like?

In my experience, you can separate an extended fast roughly into three distinct segments: struggle, flow, and excitement. Even though the duration of these stages varied quite significantly during my different fasts, I experienced them each time.

Days 1-3: The struggle is oh so real 😔

I don’t want to gloss over this: depending on the timing of your last meal, the struggle kicks in a few hours after your body does not receive the next meal at the expected time. It’s not fun. You’re cranky as you are on the lookout for a Snickers. You struggle to focus, feel light-headed or even have headaches (often stemming from caffeine withdrawal), your stomach is grumbling, and every ounce of motivation feels zapped out of you. You constantly question why you had such an unnecessary and stupid idea. You are thinking about food non-stop and realize how prevalent food is in our everyday lives: walking past restaurants, scrolling through social media, asking friends to convert lunch dates to walking dates – the list goes on.

This is the state most people who haven’t fasted before expect to last for the entire duration of the experience. Luckily, this is not the case (and I doubt many people would be fasting if it were).

Days 4-5: Entering the flow 🧘‍♂️

It seems en vogue to experiment with how to enter a flow state (whatever that even means) and everyone seems to have tricks up their sleeve that work for them. To me, a state of flow is one of little distraction, even for brief periods of time. There are probably easier methods to achieve this, but not taking in any calories for three to four days usually does the trick for me. ¯\(ツ)/¯

Especially on my first two fasts, I felt a distinct change in my body chemistry around the halfway mark. Time seemed to be moving slower, my desire to eat virtually vanished, energy levels stabilized, and a certain pleasant emptiness entered my mind.

On my first fast, I remember journaling and planning with a relaxed clarity I had rarely experienced before. The second time around I was working full-time, busting out presentations and analyses into the night. This year, my struggle period lasted all the way into days 4 and 5 and I am not sure why. Maybe it was the brutal summer heat or not having any fasting partner by my side (in contrast to the first two times). Still, I experienced glimmers of a flow state, just not for extended periods as during the two previous fasts.

Days 6-7: Excitement and ambitious self-narratives 🙌

Heading into the final days of the fasts, my mood once again switched from a relaxed, focused, and almost stoic state to one of sheer excitement and happiness. As the end is coming clearly into sight I know I’ll be crossing the finish line successfully. No temptation can bring me to falter at this moment. I even permit myself to consciously think about food and plan how I might break my fast. At the grocery store, I only pick out the freshest, most natural items and am amazed at and grateful for this abundance of food.

At this point, my appreciation for food is at an all-time high and I formulate (overly) ambitious goals to truly cherish every bite of food forever. Thoughts like “how could I ever forget this feeling and eat a nasty portion of soggy french fries” enter my mind only to be quickly rationalized by the other side of my brain half, telling me that these feelings too will pass.

Add-on: Breaking the fast

Most people are curious as to how to break such a fast. Do you crave a massive steak? Treat yourself to a huge bowl of pasta or a deep-dish pizza to make up for the lost carbs? In reality, your desires and needs at this point are much more humble: I broke each of my fasts with a bowl of self-made apple sauce (cooking and blending a few apples, a hint of cinnamon and lime – voilà). Trust me, after not eating for a week, this simple meal ignited a firework of tastes and aromas in my mouth and I enjoyed it in the smallest spoonfuls you can imagine (taking roughly 30 minutes to finish a bowl!).

It is important to slowly “wake up” your digestive system, so, for the first days post-fasting, I stuck to eating plenty of cooked veggies, nuts, berries, fresh juices and shied away from caffeine, lactose, meat, alcohol, and other tougher to digest ingredients. The joy, satisfaction, and amazement I was able to derive from each of those first meal celebrations are difficult to overstate.

What did I take away from this ordeal?

This post is already getting way longer than I expected, so here are some insights, learnings, and stats from my fasts in no particular order. Maybe one or two stick out to you or make you curious? Let me know!

🔮 Takeaways

• It truly sucks to go to bed hungry, yet this is the reality for over 700m people every day (roughly the population of all of Europe). I am incredibly humbled by and grateful for the level of comfort in my life.
• Whenever someone gets overly dramatic and hangry/cranky after not having eaten in 5 hours (it seems socially acceptable to act this way – see Snickers ads) I often think: "you could literally go 30x as long without food and be completely fine!" (of course I don't actually say this, because I don't want to be THAT guy)
• A massive portion of our day and mental space is occupied by the procurement, preparation, and eating of food (ranking 3rd behind sleeping and working for most)
• In my urban bubble, eating is an integral part of social structure. What do you do with friends if consumption of calories is not an option?

🔥 Tips

• find a buddy/support system: sharing the experience is a huge bonding moment and extremely motivating. At the very least, understanding and mindful friends help in getting you through those first days.

• plan ahead: wane off of coffee a few days in advance, make sure you have no social commitments during struggle days, empty fridge and snack-cupboard to reduce temptations, eat light meals in the last 1-2 days leading up to the fast.

• use an app: it helps to track your progress, stay motivated, and educate yourself. I used Zero Fasting.

  📊 Stats

• Water consumed: ~4L/day (mainly sparkling water to supplement some important minerals, especially Sodium)

• Weight loss: 6kg (mostly water), regained 4-5kg after 1 week

• Daily hours slept: 10+ during nights and 2-3 hour naps on top in the first days

• Mood: shaky

So, where does this leave me? And you?

The first time I fasted had a massive and lasting impact on my perception and relationship to food. I still eat junk food or shovel down a meal mindlessly every now and then, but it happens much less frequently and I am aware of this afterwards. This in itself is a huge improvement in my life, which I am not sure I would have appreciated if I had never fasted. I believe an extended fast every so often (whenever external circumstances are opportune) will be a part of my life for the foreseeable future – refreshing my appreciation for food, continuing to challenge myself, and treating my body to a zero input reset.

So, are you going to stop eating?

Shout-out to my chief reviewer Livia for her comments and feedback! 🙏