Diary of a three-day fast

For background on my fasting journey, experience and ideas, please see this post. As outlined there, my rough plan for 2021 is to fast one day a week and three consecutive days a quarter. As it’s only the second time I’ve done a three-day fast (it being nearly the end of Q1 2021), I thought it might be interesting to document it here.

Fair warning: People are interested in how bodily functions change and adapt when fasting for a prolonged period, so I’ll address that. I won’t go into graphic detail, but if you don’t want to read about bowel movements maybe skip this post.

I’m going to keep you abreast of any drinks I have, except water. Assume I start each day with a big helping of water, and continue to drink plenty throughout the day. I don’t want to combine fasting with dehydration.

Day one: Friday 5th March


I wake up with immediate pangs of hunger as well as an urgent call from nature. My poor body does not realise what it’s getting into, apparently thinking it’s important to empty itself in readiness for a normal day of eating. Boom. The first bowel movement got mentioned pretty early, eh?

For me, day one is pretty standard these days, a weekly occurrence. Not eating from one evening meal until the following evening’s meal is something I’ve done often enough that it feels comfortable.

Knowing up-front that you’re going on longer than that does lend everything a certain sense of gravitas, though.

I weighed in at 72.3 kg this morning. I’ll weigh myself again at the end of the fast. Water will of course play a part here—there’s a difference between a relatively ‘dry’ morning weigh-in vs one in the evening after a day of hydration, but it’s the best I can do. I’m not doing this for weight loss (and nor do I expect much), but it’ll be fun to see if there’s any difference at all.


I realise that I won’t get a true 72-hour fast here because I finished my last glass of date-night wine at about 23:00 last night and there’s no way I’m waiting until 23:00 on Sunday to eat.

I’ve been off processed food like chocolate, one of my true loves in life, for two weeks now and thanks to this lack of snacking the last time I ate anything was 18:00 yesterday evening, so F it I’m taking this. Purists can come at me.

I do wish I perhaps hadn’t had two glasses of red wine as my last dose of nutrition, though, right about now.

I have an espresso and re-focus on work.


Another coffee, an espresso lungo. It’s not as glamorous as it sounds—we have a nice little Nespresso machine.


I remember the delicious halloumi and falafel wrap I had for lunch yesterday. My team in work do a remote team lunch, paid for by Hotjar, every two weeks. That wrap was delicious.

I make some green tea.


I started work early today thanks to not “wasting time” with breakfast, so I clock off early, do some pull-ups, overhead kettlebell presses, goblet squats and swings. I tweaked my back on Monday and took two days off, so I’m not going to push things too hard in the workouts during this fast for that reason. Very much just punching the clock workouts, but I’ll do this little routine each day.

I head out for a short walk afterwards. It’s cold, but it’s dry and nice.


After some time with colleagues playing Mario 3D World on the Switch as a Friday social event, I go out for another walk. It’s remarkable how much time you have when you aren’t preparing or eating food. I’m only just hitting the boundaries of my usual fasting period, wine not withstanding, and I’m feeling pretty normal.

I have the usual cold hands that I always tend to get while fasting.


I jump into my regular Friday night lockdown gaming session with my brother and brother-in-law. I miss my usual beer treat, but I’m feeling pretty good and I have some nice herbal tea instead.

Pro-tip: Have a selection of healthy, calorie-free drinks on hand when fasting. I like coffee and herbal teas and I strongly recommend against diet fizzy drinks/soda because I think it tastes too close to the real thing and tickles the hunger. They’re also just not very healthy in general, I would guess. Lots of dubious ingredients.

Water can get a bit boring (though make sure you get plenty as you won’t be getting the usual water content from your food). I think that some of my intra-fast hunger is just boredom and the desire to taste something nice. Outside of fasting that’s probably the case too, if I consider my chocolate habit.

Idle thought: I’m going to start replacing chocolate with nuts and fruit (post-fast) now that I’m two weeks removed from remembering how intensely tasty it is. Too soon and I find that my tastebuds aren’t sensitive enough, and I miss the sugar.

I’d kill for some nuts or fruit right now.


Technically, the next day, but I get into bed feeling grand after a good, mostly irritability-free gaming session. I feel a little more clear-headed than I normally do come bedtime, and especially at such a late hour, but I fall asleep without issue.

Day two: Saturday 6th March


I woke a few times during the night but nothing too out of the ordinary for my non-blackout-blinded apartment bedroom. I’m up early, and after less sleep than I’d like or advocate because I’m going to meet a good friend for an outdoors, COVID-safe walk around my area. Not only that, but I’m also trying to have more of a consistent wake-up time in general, so if I stayed up too late last night it’s my fault. I have to deal with it. Alright, six-ish hours isn’t the end of the world, but I’ve learned through experimentation that anything less than seven doesn’t suit me, and, ideally, I’d get closer to 7.5 hours of sleep.

Out of habit, bodily functions compel me to head to the loo again first thing. Kind of a surprise. Some people report having some extremely odd bowel movements on three day plus fasts, as if their bodies are purging old, accumulated grunge. This is more common on day three, though I didn’t get anything like that my first time, and again so far so normal. Volume is predictably low. I hadn’t factored in the toilet break when setting my alarm for as late as possible.

It will be somewhat interesting to see how such “little” sleep affects my hunger levels. It’s pretty accepted at this point, both anecdotally and scientifically, that we tend to eat more when we’re tired. This is likely due to our bodies trying to make up for a lack of sleep by compensating with more calorific energy. I can say for sure that I’ve noticed this in myself.

I try to push this thought to the back of my mind as I power-walk, bleary-eyed, into the crisp morning.


Back from the walk. My friend, who was not fasting, brought me on a great, three hour/15 km stroll (a big circle within our 5 km allowed zone, don’t fret) that definitely tested me. I’ve found before that it’s longer duration exercise activity that suffers for me when fasting and today was no exception. I kept going because a lot of my goal with the fasts is to act like I’m not fasting, and asking to stop and sit down for a few minutes would be pretty anomalous from a 32-year-old fitness enthusiast, but I felt it for sure.

It was great to get some social contact. We had a lot to catch up on, having not seen each other in months, and something simple like walking and talking with someone you don’t live with is a real treat nowadays. It was also just nice to walk. The best thing to come out of lockdown life is how much I appreciate simple walking these days.

I had a black coffee (americano) at around the halfway point, and had myself an espresso when I got back. I feel cold, and a bit tired, but pretty golden all things considering.


I spent the last two-and-a-half hours writing, something I haven’t managed to get myself to do in quite a while. I wrote the fasting background post while fasting, both because I’m a huge fan of that Xzibit meme and because writing about my relatively successful fasting history felt motivating, like a little “See? You can do this!” to myself.

Day two is widely considered to be the “hardest” day for most seasoned fasters, and I think I get that. For me, it’s the day that my body realises something different is going on. I get a little tired of the cold hands (is this just me that gets cold hands when fasting, I wonder?). I get hit with more intense hunger pangs at times, and it’s essential for me to stay busy.

On the plus side, I’m also feeling clear-headed as F, much more-so than I would after a night of sub-seven hours sleep when I’ve been eating normally. That’s partly, I’m certain, why I’m able to sit down and hit flow state while writing for going on three hours now, and even felt the motivation to do so in the first place. Is it possible some of that is down to my body not using energy for digestion? Maybe. It’s also possible that my body is in a very low-level alert state, and is giving me a bit of adrenaline.

My mouth is starting to feel the lack of food. It’s cotton-y after the two coffees, as if I’ve been snogging a pillow. I probably need to drink more water than I am.

I’m hitting the latest time of day I’d ideally get any caffeine, so as it’s now or never for a “novel” flavour today (I only have two decaf teas available, so I don’t want to miss the opportunity to taste the caffeinated tea as well), I’m getting up to do my little workout and then prepare some green tea as a reward.


Played a session of video games following my workout, which went fairly well. It’s just hitting dinnertime now so everyone was talking about their meal plans. It makes for uncomfortable listening but I’m good.

Interestingly persistent aches and pains, I notice. My right elbow, perhaps from pull-ups or pushups, and both my legs from the long walk. To be fair, it was about three times longer of a walk than I’d usually do in one go, and in barefoot shoes, and fasted, so it does make some sense.

Another point of note is that I do seem to be slightly more susceptible to anxious thoughts or sensations in this state. Nothing crazy—I’m making a lot of progress in this area—but it’s somewhat noticeable this evening.

Just did a session of meditation with the Waking Up app from Sam Harris, which was thought-provoking as always. It really does feel like a training programme for the mind rather than just a relaxation tool. I’m learning a lot.

Dinnertime day two is probably the apex of three-day fast difficulty, so I’m looking forward to having ridden this one out. I will do an hour of work and then enjoy some tea.


Work complete and feeling a little more grounded than I was. Perhaps I’m over the worst over it? I can but hope. Time for some nice, herbal tea.


Just finished watching Gangs of New York for the first time. I think my quick review is: Some good acting, better accents than I expected, interesting history I was unaware of before, but ultimately disjointed and not recommended.

Disclaimer: it’s entirely possible I would enjoy the movie more on a full stomach.

I think I’m over the hump on this fast, but it must be said that despite being a vegetarian for the past four years or so, I felt my mouth watering watching Bill the Butcher eat a steak. Not that I’ll be running out to eat a steak or anything like that, but it’s a sign of how hungry I am.

My legs and elbow are still aching a little, but overall I have a nice, calm feeling suffusing my body. I feel light when I take a deep breath, like I’ve started to float around instead of walk. I’m pleasantly tired, but my thinking feels clear.

I’ve had one more cup of herbal tea but, with nothing else to keep me, I think it’s time I hit the hay. It’s been a very productive day.

Now I’ll journal, read, and hopefully enjoy a good night’s sleep.

Day three: Sunday 7th March


Awake, heart absolutely racing, pounding headache.


In short, I feel as rough as a badger’s behind.

I managed to fall back to sleep after the earlier episode, but it’s very broken sleep. When I wake up this time I feel like crap and, most concerning, my heart is still racing a mile a minute. My head is throbbing and foggy. It feels like a (very) mild flu.

I down 500 ml of water and visit the toilet this morning again, with more volume than yesterday. Very surprising.

While googling for my fasting problems, I come across the idea that by this point autophagy is in full swing in the body and some of this is accumulated dead cells and such. I’m not sure I fully buy it, but… sure. Let’s go with that.

In an uncharacteristic move borne of feeling like shit, I wind up watching YouTube videos on my phone for nearly an hour, lying on my bed. Not even watching in many cases—merely adding them to my Watch Later.


I think I know what’s going on, and it’s embarrassing.

My first three day fast was a pretty chill experience. I’d just read Dr Jason Fung’s book and I was armed with good, fresh knowledge about fasting. In particular, I learned a lot about intra-fast supplementation.

It basically comes down to salt intake, I think. In my first three-dayer I was supplementing with a little salt in my water, keeping my sodium levels up to avoid flushing all the minerals out of my system and keep my nerves, muscles, heart etc all ticking over nicely.

This time around I completely forgot that wrinkle, and have been freeballing with just coffee, tea and lots of sweat-inducing exercise. Sure, at no point was I dripping sweat, but I was absolutely sweating at times—most notably during the exceptionally long walk I went on yesterday. Currently I’m feeling like an idiot, but that’s how it goes. Would this be interesting if I was a complete expert and never made any mistakes?

Who am I kidding? You’re just here for the BM talk.

In a bit of a panic—it feels a little like constantly panicking when your heart is doing 90—I put 15 twists of a table salt dispenser into a 300 ml glass of water and downed it. It was like downing seawater. In hindsight, I should have been adding small amounts of salt to my water the whole way through, as the past—much smarter—me was doing.

I’ve added a few twists to my 500 ml bottle of water also and will sip at that over the next hour.

If I get to 10:00 and I’m not feeling substantially better, I’m going to end the fast early and call it a learning experience. I’m in this for health benefits, not for self-torture.

In case you’re curious, and given the fast might end a little prematurely, I weighed in just now at 70.1 kg. Considering I’ve drank around a litre of water already today, that’s an impressively low figure. 2.3 kg lost so far after roughly 63 hours fasted.

Now I’m off to order some Himalayan pink salt and take it extremely easy for an hour.


The plug has been pulled. I enjoyed a coffee on my balcony (with a little added salt) but systems were not recovering quickly enough for my liking, and my girlfriend was adamant I looked as unwell as I felt.

I broke the fast with a scoop of Athletic Greens (trying to get in nutrients) a bowl of muesli, a small orange, and some toast with peanut butter and banana.

Kind of anticlimactic compared to last time, when I broke my fast with a big pizza and chips, but I’ll take it.

Total fasting time: 65 hours.

Seven hours short, but I’ll take it.


Back from a nice walk in the sun on which my feet really started to drag. The best comparison I can make is that I feel moderately hungover. Not “I’m on the verge of puking constantly” level, but only a couple of notches below that.

Food shop is done, during which I found I couldn’t really think about what we needed or plan properly—decision-making was out the window.

Going to eat a sandwich now, and I’m dreaming of pizza.


Dinner was a tiny Pizza Hut pizza, garlic bread, chips and a Linda McCartney vegetarian burger. No bun, though, ‘cos, ya know, healthy eating and all that. Ahem.

I was ravenous, the sandwich, apple and orange earlier barely making a dent in my hunger. I don’t even feel full now, but I’m not going to eat any more and see if my hunger levels and how I feel will start to even out and come back down from orbit.

Even better, Manchester United beat Man City today. The good guys do triumph sometimes.


About to hit the hay—very tired after a weekend without too much sleep. Feeling a little more normal now. It’s possible I really needed the huge injection of sodium that the chips and pizza provided. It’s also possible that, as with hangovers, the greasy food magically gave me new life.

Addendum: Monday 8th March


Woke up today feeling nearly normal. Looking in the mirror I think I look a little leaner, though it wasn’t the goal per se. Most interesting of all is that, after weighing in at 70.1 kg yesterday morning (feeling like crap at around hour 61 of the fast), despite my gluttony yesterday evening I only put on 0.1 kg since, for a weigh-in of 70.2 kg today.

I’d expected to be back up to at least 71 kg, with glycogen stores replenished, food in my system, and water retention probably up thanks to the sodium.

Given I was physically active throughout the weekend, with my minimum dose pull-up, press and leg exercise routine plus the walks, I seriously doubt I lost much or any lean mass.

I’m hesitant to draw the conclusion that I lost 2+ kg of body fat, though, as that seems absurd. I’ll continue to weigh in for the next few mornings. If it was really body fat that I lost I would expect my weight to stay stable-ish rather than rocket back to the previous status quo of 72-73 kg.


I didn’t successfully complete the 72 hours, but I’ll go into the next attempt knowing more than I do now.

I have no regrets about ending it early, which I feel good about because I think even a month or two ago my headspace was gloomy enough that I’d probably be beating myself up about it without the work I’ve been doing to improve it. I held out as long as I reasonably could while still being able to say my goal was to be healthier as a result of the fast rather than a pure bloody-minded willpower challenge, health be damned. The image that finally convinced me to eat was one of me turning up at A&E in the middle of a pandemic and having to sheepishly explain I was so unwell because I’d voluntarily starved myself for 3 days. Yeesh.

My main takeaway for future attempts will be to ensure I add small amounts of salt to my water and avoid long-duration exercise on my next multi-day fast. I’m not dissuaded from giving it another go. If anything, I’m actually feeling a little bit of impatience to try it again. I will wait a while, though. I still feel slightly off-kilter this morning and I know better than to tempt fate with a rushed attempt. 65/72 hours isn’t far enough off for me to feel it was a total failure that needs to be urgently repeated, and I feel pretty positive about the whole thing.

Of course, that could be because I weigh 2 kilos less <insert trollface meme>.

A week later, I was still down the weight I lost, so at this point I think I am saying it was fat loss. Remarkable!