#Monthly experiments / Healthy

How I stopped eating for 78 hours (my 3 day fast during Month 1 experiment)

I fasted for 78 hours. It was not for political or religious reasons, this was purely selfish thing I did for my Titan Experiment, as part of the month long experiment with ketogenic diet and fasting.

How can fasting be selfish? I did it because I want to live a good long life.

In this article I cover:

  • Why you should consider fasting
  • How does it feel
  • Why it’s good to find a fasting buddy
  • Ghrelin – the hunger hormone, and how it is different for men and women
  • How it went – Personal experience, day by day
  • Main takeaways – How to prepare for the fast
  • Main takeaways – Benefits of fasting (health, calm, resilience, …)
  • Conclusion


Why you should consider fasting

The health benefits of fasting and its impact on longevity are becoming very clear.

It’s not particularly new topic, but it’s becoming more and more wide spread as more and more research points out interesting links between fasting and improvements of different conditions, as well as pathways that might explain how the improvements are achieved. Not to mention the sudden popularity of research showing all the negative impacts of feasting – from diabetes through cancers to Alzheimer’s and beyond.

How does it feel

I am already doing 24 hour fasts regularly for some time, but I’ve never tried extending beyond that. Still, the whole experience was surprisingly …normal?

It might be because I was well mentally prepared, or because I was in ketosis for some time before I started, but I had no issues reported by some others during their second or third day.

Evolutionary speaking, our ancestors – going back to those who first incorporated mitochondria as part of their cells – went through periods of feasting and fasting, and our bodies have reasonably good energy systems for both situations. We may have not used it because of the abundance of food in the western world, but the circuitry is there (albeit a bit rusty).

Fasting buddy

The most surprising thing was that my husband Tomas joined me for full 3 days.

His father used to say Tomas is “either eating or hungry”. He is a lucky super-burner so he can eat anything and all the time, and never get fat. And he uses it to the fullest extent. When we met he would enjoy lots of unhealthy foods, but he gradually moved to the manliest diet of all – primal/paleo diet, mainly to improve his sleep. Then maybe a year ago he switched bulletproof diet (with occasional ice-cream and potato chips). Recently he tried ketogenic diet as well, but said it didn’t work for him.

He got quite interested in health and nutrition, but never in terms of “no nutrition”. Anytime I do my weekly one-day fast, he would give me these “woman, you are crazy” looks. Yet, he suddenly decided to join me.

I’m so glad that we had this experience together.

I’d write “that we suffered through this together”, but it was not really suffering, except for Tomas being more sensitive to food smells. I was enjoying smell of food without the temptation, but he was commenting a lot on how much he misses the flavor of food. Especially on Thursday evening (Day 2) when we brought our friends to our favorite Szechuan restaurant (service is terrible there, but the food always tastes and smells really good).

Ghrelin – the hunger hormone

The second most surprising thing for me is that for the whole time I was not feeling hungry.

Once or twice a day I would feel hungry for a minute, and then it would pass and I’d be OK again.

GhrelinThis will be different for men and women – at least research would suggest so. The hormone responsible for our feeling of hunger is ghrelin, and its daily changes in levels seems to have a different curve between these two groups, and different reactions to 3 day fast. Interesting is that for women the ghrelin levels are slightly higher and have larger differences during the day cycle (that might explain more intense food cravings in women?), but also our reaction to fast is more intense – ghrelin goes down significantly on day 3. Read more about effects of fasting on ghrelin in this article.

How did it go – day by day

Day 1


Last food

In preparation of fast, I started Wednesday morning with BP coffee. Lunch was a bit of a ritual – I bought salad of veggies with egg and salmon, took them to a nearby park and ate there, alone, savoring every bite, one by one. This was to be my last meal for next 3 days.


In the evening I met friends who came to Singapore for a data science conference and took them to Lau Pa Sat hawker center. I drank water while chatting with them and watching them eat. After that I joined Tomas and our friend in a local pizzeria (we drank water, and I think he felt a bit embarrassed).

Day 2

On Thursday morning I was still feeling pretty good, and I took half a dose of KetoForce just to test it out. It did not impact my Ketonix score, which I could’ve expected since it measures acetone and KetoForce is beta hydroxyl butyrate. I went to work and had a nice walk instead of lunch. That evening we met our friends again and took them to a Szechuan place with awesome food, where we had water again.

Day 3

On Friday I worked from home. Despite heavy use of lavender and piano music it was quite stressful because in the morning my boss told me that on top of all the the work I had to finish before our trip to Europe, I also had to do something I was not expecting. Not an ideal setting for third day without food.

I was really freaking out to make it all done, and around 4pm I managed to accidentally delete almost all the data from my corporate notebook, just to find out that it’s not backed up automatically. Still, I took it surprisingly calmly. I took a few deep breaths, did everything I could to be able to recover the data after I return, turned off the notebook and started packing.

Our last 20 hours were spent flying from Singapore to Slovakia. I wonder what the flight attendants thought about the couple who would refuse to eat anything and just ask for water a lot. On the other hand we were wondering whether the Turkish Airline food really looks so good, or it’s just our perception.

Day 4 – refeeding

Place of our “refeeding” in Bratislava was picked by my (very picky) father in law – Czech restaurant Kolkovna in Riverpark Bratislava (don’t go to the other one).

first-lunchTo break our fast after 78 hours, we ordered chicken broth (I asked to have it without chicken and noodles so I got extra veggies). Both choices – the place and the food – turned out to be great ideas. I can tell you that the soup tasted like heaven, even the parsley which I don’t like usually.

We couldn’t help it and tried small bits of our friends’ meals, and they all tasted like heaven. We ended up ordering and sharing a salad with goat cheese. With each bite I was very concentrated on the flavor, eating each ingredient separately and enjoying it to the fullest. It was a great reminder how great the food can taste, and that I should enjoy it more mindfully.

I admit that the goat cheese might have been a bit risky, but luckily I had no issues whatsoever to digest the food, and later in the evening I also happily ate buttered trout baked by my parents. We didn’t go overboard with the food portions to compensate for all the missed food. On contrary I ate less than usual, and felt good.

Main takeaways – How to prepare for the fast

  • It probably helps if you are in ketosis / fat adapted before you start fasting
    If you have no time for that, Tim recommends brisk walk for a faster kick into ketosis. Or MCT. Or you can do both, just in case.
  • If you mentally prepare for it, 3 day fast is not difficult at all. Small ritual might help to get you into right mindset.
  • Prepare your kitchen as well, finish stuff that could spoil. (we ended up throwing a lot of things away because my husband decided last minute and then we traveled)
  • Find a fasting buddy. I’d do it alone, but it was so much better with Tomas. Can fasting be romantic?
  • Don’t forget about minerals. Drink salty water at least once a day. Have salt on hand in case you needed.
  • Plan pleasant activities for lunchtime and evenings to get yourself busy.
  • Plan well for the last day – it should be relaxed, lest you want to end up doing something stupid like I did (accidentally deleting data)
  • Re-feeding needs to be planned as well
    Just start with something light (broth worked well) and then eat like you have not fasted at all.

Main takeaways –  Benefits of fasting

  • Longevity, health
    There’s tons of articles online on how different forms of fasting (intermittent fasting, 3 day water fast, 5 or more day water fasts, fasting mimicking diet, etc) have positive influence on health span and life span. I’m not a doctor so I will just recommend you research the topic if you are interested.
  • Physically, you might feel no or just very little hunger
    How you will feel mentally will probably depend on your mindset.
  • You’ll get a lot of free time. And I mean a lot
    I realized how much time I spend by thinking about, gathering, preparing and eating food. It’s probably a few hours every day.
    You won’t save much toilet time though – we both stopped pooping on 2nd day, but you drink a lot water so you still have to go.
  • Good sleep
    “Sleep efficiency” and “Deep sleep” from my Oura ring were almost 100% each night (except for flight obviously), I woke up well rested. This is contradicting reports by other people who reported worsened sleep patterns. Maybe it was because of the next point – how calm I felt.
  • Calm
    I felt calm and balanced, to the level when even the desperate situation of deleting 6 months of work couldn’t shake me that much.
    It might not be direct result of fasting on biological level, but more about the psychology. It’s definitely a good uplifting feeling that you’re passing the challenge that you’ve given yourself, that you are overcoming one of your fears. No wonder most of the religions incorporated fasting practices.
  • Mental and physical resilience
    Now I know I can last 3 days without food. I know I don’t have to “eat this thing right now otherwise I will suffer and die”. And I wonder what else I can do what I previously considered impossible.
  • Flavors
    Last day I was not really worried about food as a source of nutrition, but I was craving for flavors. A few days after the fast I didn’t have to remind myself to enjoy the taste of everything I ate. Each flavor would give me a bit more joy than usual.
  • Weirdness of re-feeding
    During the flight a girl sitting next to me ordered special seafood meals. All of them looked very pretty, but it was very weird for me to think to put something solid into my mouth and eat it. If you think about it it is a bit weird – you take a piece of animal or plant, put it into your mouth, chew it, ingest and then your body breaks down that piece of organic material and use it to build pieces of you, or energy.
    Luckily this went away pretty quickly as I’d put first spoon of chicken soup into my mouth 🙂
  • Want to do more
    We agreed that we will do this again soon, and we will do it regularly.
    Which is good, because shortly after we finished the fast, Q&A podcast with Rhonda Patrick was released, where she speaks that some of the most interesting processes only start on day 4 of fasting. Shacks. But it’s OK, we can do 5 days, we just need to plan to spend at least last two days somewhere in nature.


Health benefits on side, fasting is a practice that improves mental well-being. You build resilience, confidence and it might even reduce your fear/anxiety. Once you know you can go for 3 days without food, you might be more willing to accept some adventure.


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4 thoughts on “How I stopped eating for 78 hours (my 3 day fast during Month 1 experiment)

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