My Three-Day Fast

I finally got around to doing a three-day water fast. I’ve been doing weekly 24-hour fasts for a few years, and when a co-worker mentioned doing one together, I thought it was the perfect chance. Altogether, four of us in the office fasted: one dropped out after 24 hours, two fasted and recovered just fine, while I had some issues post-fast.

The purported benefits are myriad: increased insulin resistance, better ability to burn fat, autophagy rapidly replacing old cells and a massive boost to the immune system.

The Day Before the Fast

I ate moderately low carb meals and had a nice meat and veggie heavy last meal. I also spent a week tapering down my caffeine intake. I’m glad I did this, as I ended up not having any withdrawal symptoms during the fast.

The First 24 Hours

Since I’m used to 24-hour fasts, there was nothing out of the ordinary here. Obviously there was some hunger but nothing dramatic.

Hours 24–36

This was the worst part. Hunger and weakness set in.

Hours 36–72

Hunger more or less abated, but I was still rather weak and sluggish. My perception of time really slowed down, but my concentration on whatever task I was engaged in was higher than usual.

This part of the fast really wasn’t that bad. As long as you don’t have any physically taxing things to do, you can easily forget that you haven’t eaten for a couple of days.

Breaking the Fast

I had some chicken broth to break the fast. As soon as my digestive system turned back on, everything that had lingered in my intestines decided to make an immediate exodus. This didn’t happen to the two others who completed the fast with me, so who knows what the deal was.

By the next day I’d worked up a pretty serious appetite. Unfortunately, there was a ton of junk food in the office. My stomach didn’t enjoy this. My advice is to really be conservative coming off of a fast, although this does seem to vary for different people. I do nothing special after a 24-hour fast, but 72 hours hit me harder than I’d expected.

Observations from the Fast

General noting and mindfulness is more interesting during a fast. Hunger is not a solid feeling; it comes and goes. The brain plays tricks on you and seems to pretend you are weaker than you really are — I’m reminded of how Tesla battery life is determined by software rather than actual battery capacity. Expect to be cold; the body saves energy by turning down the thermostat a bit.

While I was engaged in something, the background chatter in the mind ground to a halt. I think I was more productive than usual at work, but this is because I mostly have tasks that require attention to details rather than brute mental force. When I sat down to meditate, I found a lot of power and energy in my meditation. Yes, I could concentrate on my breath or mettā but nothing more. This surprised me as hitting the first jhāna is pretty routine for me on a regular day.

A lot of people on the internet complain about trouble sleeping. I was out cold long before my regular bedtime but would wake up for a couple of hours in the middle of the night. I still got about nine hours of sleep each night of the fast — more than my typical seven. Dreams were incredibly vivid.

The Take Away

I’m glad I did it, if only for the psychological benefits. It’s satisfying to complete something that most people would consider difficult if not downright impossible. I’m not sure if I’ll do it again, though. It’s hard to know whether the benefits of a three-day fast are that much greater than going for only 24 hours without food. A longer fast definitely puts more stress on the body making it hard to calculate the actual payoff.

I’ll definitely keep up with 24-hour fasts once a week or so. I might play around with a daily eating window to see how that compares. In any case, it’s worth doing at least one longer fast just for the experience.