What I Learned From My First 24-Hour Fast

Fasting is nothing new. Religious practitioners the world over have used fasting as a way to deepen their relationship to and dependence upon God for millenia. And it’s been recognized for it’s health promoting benefits for just about as long, with Hippocrates and Plutarch having recommended fasting as medicine. Upton Sinclair even wrote a little known book about fasting in 1911 in which he advocates “the benefits of systematic fasting in producing long-lasting health benefits.”

Our hunter-gatherer ancestors also went for long periods without eating, involuntarily fasting while searching for food. This may be why so many religious traditions associate fasting with the winter months, when food was especially scarce.

fasting in the christian religion
Return to me with your whole heart, with fasting, and weeping, and mourning; Joel 2:12-13

Today, fasting, especially intermittent fasting, has re-emerged in the cultural zeitgeist, especially amongst millennials and Gen X-er’s (or so it seems to me, since these are my peers and is a topic conversation that comes up), nutrition and fitness gurus, and generally amongst people with disposable income. I’ve been deliberately or accidentally intermittent fasting for years, but today I’m doing my first 24-hour fast and I’m going to give you the full account below.

Why Am I Doing a 24-Hour Fast?

I’m fasting for 24 hours for the first time because I’ve always wanted to try it, and frankly, I currently feel desperate to avoid food. I’ve been traveling, living in Mexico, and thus a bit gluttonous, wanting to eat everything! Remember the “always calorie restrict, dietary restrict, or time restrict” dietary framework by Peter Attia I wrote about? Yeah. I have not been adhering to that. Nor have I been “feeding my soul.”

Instead, I’ve been indulging my cravings, eating past the point of fullness, mindlessly snacking, and generally partaking in all the things that eventually make you go UGHHHH!!! Last night I experienced so many of the drawbacks of my poor habits it seems to have been enough to announce to my partner that I wouldn’t be sharing any meals with him the next day and that I wanted to fast for 24 hours. 

Photo of me two summers ago enjoying my favorite beverages. Not fasting. Though these are semi-acceptable fasting beverages minus the milk obviously. Unacceptable disposable cup. Oops.

I’m fasting as a way to hit the reset button. To get back in touch with my ideals around eating, to gain back a sense of humility and appreciation for the abundance of food there is to enjoy, and my position in society that I can access it. And well, honestly, hopefully to just de-poof my stomach…

I’m not going to go into a lot of detail on the benefits of fasting, as there is already an abundance of science-backed info out there on all the reasons why we should all fast much more often than we do, not only to improve body composition, but also to increase energy, reduce “brain fog” and increase our overall longevity.

Without further ado, below, you’ll find my hour-by-hour breakdown of my first 24-hour fast, and what conclusions this experience led me to.

grocery shopping at city market in monterrey mexico
One of the few times Michal and I have used a grocery shopping cart. And that’s Michal, not me, eatng the jelly filled donut on the way out the store. ?

“Everyone can perform magic, everyone can reach his goals, if he is able to think, if he is able to wait, if he is able to fast.”

― Hermann Hesse

My First 24-Hour Fast: Hour by Hour Breakdown

11 AM the day before: I had two eggs and half a pancake for a late breakfast along with our usual “upgraded coffee.” I usually eat 3-4 pancakes with lots of butter in the mornings, depending on their size (we are a little bit obsessed with making pancakes lately!) but today there was only enough batter left for one.

2:30 PM the day before: I heated up some leftovers for lunch– taco filling of sweet potato, spinach and mushroom. I added cheese and we had delicious quesadillas.

9 PM last night: This is when I finished my last meal, lets say, to be safe. Michal and I ate out (unusual for us) after visiting the Desert Museum in Saltillo. We visited two restaurants – both of which offered practically no vegetarian options, which is not surprising for the region. We ordered basically appetizers, huitlcote quesadillas, quesadillas de champignons and shared an order of super-fresh-made-in-front-of-you tortillas de maíz with a side of avocado.

Then we went to another restaurant in hopes of a better vegetarian selection. The food selection was barely better. We had one choice – sharing a chili poblano relleno with espinaca. Pretty good, but pretty basic, kinda like a Mexican version of American pub food. They had a nice mezcal selection, though, so we tasted a few kinds and shared a beer. That was the highlight for sure!

After dinner, I felt terribly over-full. It’s pretty rare that this happens, that I get so full I feel actually sick and it’s literally hard to breathe! This could have been caused by either what and how much I ate, and/or the fact that I’ve been drinking a lot of water since I got dehydrated 2 days ago while climbing a 12 pitch route. Or the fact that I’ve just ovulated, so my estrogen and progesterone are higher, leading to increased constipation…I hadn’t had a bowel movement at all on this day…which isn’t good… is never good… especially because I mowed down a solid amount of calories the day before, including like 12 Chips Ahoy style cookies. Ok, I’m done sharing too much information now. 😉

10:30 PM last night: after deciding to fast, before bed I took 1 1/2 teaspoons of magnesium to hopefully help “move things along.” I go to sleep.

10 AM the next day: I tried to sleep late. The longest fast I’ve ever done was about 20 hours, and I achieved it by sleeping until almost 2 PM! Today’s fast is the first thing I think of upon getting out of bed. And I feel disappointed. Vague feelings set in of what do I even have to look forward to today? I’m still committed, though realizing how much of my day I normally spend thinking about food…planning a meal…preparing a meal…cleaning up after a meal…looking forward to a snack….seriously: what is the point of existence without food again!?

10:15 AM: Bowel movement! I didn’t have one at all yesterday… Thank. God.

10:30 AM: Michal makes me a cup of green tea and I read a little from my book. Michal is making himself oatmeal with a perfectly ripe looking mango. I’m a little sad.

11:40 AM: I feel a few small pangs of hunger and go about some morning chores. 

1 PM: I’m now about 16 hours into my fast? My focus has shifted to doing other things, and I’m not feeling concerned about food. Though I’m looking at my kiwis and thinking they are perfection.

What perfect little fruits.

Nature really outdid itself with kiwis.

2:45 PM: Fasting is dumb. I’m hungry. We’re grocery shopping at our favorite store in Monterrey. There’s so much beautiful food. We leave with our bounty, including pastries. Time is passing slowly. I love food! 18 hours…people routinely fast for 18 hours as a daily habit! I’m noticing my weak mind.

3:25 PM: This too shall pass. Time is creeping slowly. We’re going to climb a couple routes. Hopefully it takes my mind away from my self-imposed abstinence from all the delicious food. Food is art! Food is sacred! Michal is scarfing pastries. My belly is still bloated.

7:20 PM: I’m feeling pretty good. My tummy has settled, but I still “look” full and have a protruding lower abdomen, which I am concluding must be connected to general inflammation. Hmmm…

Breaking My First 24-Hour Fast

8:15 PM: I’m counting down the minutes. Planning how I will break my fast. Isn’t this the crux of fasting, anyways? Not gorging yourself and reversing all your hard work?

When I worked at Kion we did a very memorable and super successful Fasting Challenge. To promote it, I planned a ton of social content. Thousands of people participated! One post I created that’s stuck with me was about some of the best ways to break your fast.

Thomas Delaur on things to consider when breaking your fast.

Personally, I’m craving eggs. Lovingly preparing and mindfully savoring salty, pastured eggs. Mmm. Three or four? Cooked slowly over low-medium heat with pastured butter. I also got a small focaccia roll, which sounds pretty nice to dip in olive oil and balsamic alongside the eggs. But my reptilian brain also wants my sweet croissant, one of the pastries I got for myself…woah! That is a lot though.

9:00 PM: Ding! I made it! Time to make eggs!

9:22 PM: 22 minutes later, I cooked 3 eggs in our cast iron pan with lots of salt and butter and enjoyed a piece of focaccia with olive oil and balsamic. Super rich and satisfying! But I’m definitely craving something sweet, even though the balsamic was pretty sweet. So I’ll have a kiwi and trick my brain into this being dessert.

Considering my activity level (super low) the last couple of days, even this many calories just now between the calories from the butter and olive oil and bread are almost certainly more than I needed. But I enjoyed every last bite of my meal, and it felt nice to love what I was eating. Soul food.

erin demarco savoring an in season colorado peach
Me savoring a perfectly ripe, in season Colroado peach during a brisk morning hike.

Takeaways From My First 24-Hour Fast

In conclusion, I’ve realized the following from this experience.

  1. Doing a 24-hour fast is not that hard! Ok, this is admittedly easier to say now that it’s over. It was daunting at first, but now that I’ve done it, I know I can do it again.
  2. I had even more trouble than usual living in the moment. All day my mind was fixed on a fitire event, dinnertime. However, it was hard to take my mind off this mental countdown to dinner and time dragged on. Staying in the moment was really hard because the time period was short enough that my mind could focus on reaching this specific future point in time, instead of being where I was.
  3. Next time, I want to go an entire waking day without eating. A lot of people time their 24-hour fast to go from dinner to dinner. This supposedly makes fasting easier. You eat dinner, go to bed satiated, then just have to go until eating dinner the next day. Not that bad! For people who fast for 24 hours on a weekly basis, this seems like a realistic way to do it. However, it feels like a bit of a “hack” to me. Instead of abiding by this familiar convention of 24 hours, I think fasting for 36+ hours, where you eat dinner, go the entire next day without eating, and then have breakfast the following day, would be a richer experience. And it might actually be easier in way. My mind might be able to relax a bit more, knowing that eating that day just wasn’t happening at all.
  4. Fasting for 24 hours felt like just the beginning. By the time it was time to beak my fast, I’d actually just gotten somewhat used to my new-not-eating-normal and I had some desire to keep it going. My mind of course was excited to eat, but aside from a few hunger pangs in the morning, my body gave me very little indication that it was hungry or that I needed to eat. For me, it felt like the first 24 hours of what should have been a longer period. I can definitely see why people do extended fasting for several days. It’s hard to really settle into the experience in just 24 hours, and less than one waking day.
  5. I would like to make fasting a habit. Fasting once was cool, and surely had some measure of positive effects, but I know better than to think that a sinlge 24 hour fast is going to do muhc for me. Fasting for me would probably be easiest right after my period. One thing I’ve learned from tracking my menstrual cycle is that I usually don’t experience many cravings or have a strong appetite in the first few days after my period.

In Conclusion

I feel better than before my 24-hour fast! There’s no doubt about that. My stomach has de-bloated at least a little bit, and I feel mentally clearer. A small milestone achieved. Next time I fast, I want to fast for 36 hours or more, and ideally, I’d like to keep it up. I like the idea of going an entire waking day without eating, having breakfast the next day, continuing to restrict calories that day, perhaps have a light dinner if any, and then go back to normal eating after 48+ hours. I want to have deeper experience with fasting, instead of just feeling like maddeningly obsessed with the clock ticking time away. Goodreads has a nice list of literature on fasting from a spiritual perspective, which interests me. While I’ve become quite familiar with the health benefits of fasting, I’m also looking forward to fasting as a way to train my mind and develop spiritually.