Prolonged fasting

My experience with prolonged fasting

Disclaimer: I am not a doctor so whatever you do is up to you.

Why fast for multiple days? #

If you're healthy, then it's a great way of exposing your body to a healthy dose of stress. Your body starts to burn any weak, malfunctioning, or old cells it can. There is some evidence of helping with some versions of cancer as well. It's not a magical cure, but if you have some excess body fat to lose, you can get healthier (in the long term) and lose some fat simultaneously.

I can recommend some articles:

First long fast (5 days and 12 hours) #

It was inspired by Angus Barbieri's fast and some new science about the benefits of fasting.

In summer 2018, I tried prolonged fasting for the first time.
The First 3 days were pretty hard. I felt hungry and tired all the time. Fortunately, you can drink coffee and tea, and it helps.
After that, it got much better. My feeling of hunger disappeared. I lost 1kg (2.2 pounds) every day and used coffee and tea to keep me energized.
Unfortunately, the longer I went, the less well I started to feel. I began to get a little dizzy, and it started getting worse.
I've broken my fast after 5.5 days of not eating anything. The moment I started eating (slowly and in small portions), I started feeling extremely hungry. It was tough to keep myself from devouring everything in the fridge. You should begin to eating slowly; the digestive tract wasn't used much for a couple of days, and overeating is not a good idea.

Overall, I lost around 3 kg (6.6 pounds) and instantly felt better after I started eating.

Curious about what I was doing wrong?

Second long fast (8 days and 16 hours) #

September 2022. This time I knew more about fasting. I've added some changes:

The first day was without any problems. I'm already doing Intermittent Fasting, and I suspect it helped me here.
For the next 3 days, I was constantly exhausted and hungry. This time I didn't bother with tea. I drank coffee in excessive amounts to keep working.
After my body switched to ketosis, I stopped feeling hungry and started feeling much better.
I still had low energy, but I was able to drink a lot of coffee to keep myself going.
My target was 7 days, but I felt so good that I kept going.

I could do only a little exercise, so I didn't want to fast for too long. The first downside of prolonged fasting is that exercising is extra hard. But your body is consuming not only your fat but also your muscles. Exercising should help with that if you can do it.
The second downside is missing the fun of sharing a meal, so I put the finish line at 8 days and 16 hours of fasting.

I started eating Olives, a bit of sauerkraut, and a vegetable broth over the first couple of hours. I didn't get extreme hunger like before. I suspect it's salt or electrolytes. But, it can also be that I started with food rich in fat, which still keeps me in ketosis.

This time I lost 5,2 kg (11,46 pounds).

I drank a lot of coffee, but curiously I didn't get jittery regardless of the amount of coffee I drank, which sometimes happens to me outside of fasting.

If you want to try #

  1. Consult your doctor
  2. Read:
    1. Amazing Benefits of Prolonged Fasting author avatar Dr. Eric Berg
    2. 15 Best Foods to Break a Fast
  3. Buy a lot of coffee ;)


Share on Hacker News
Share on LinkedIn


← Home


Want to learn more?

Sign up to get a digest of my articles and interesting links via email every month.

* indicates required

Please select all the ways you would like to hear from Krzysztof Kula:

You can unsubscribe at any time by clicking the link in the footer of my emails.

I use Mailchimp as a marketing platform. By clicking below to subscribe, you acknowledge that your information will be transferred to Mailchimp for processing. Learn more about Mailchimp's privacy practices here.