For as long as I can remember I’ve had one problem with my weight — there was too much of it. It never had a serious impact on my life, but at 110kg and 190cm (242lbs and 6'3" for you Yanks, Liberians and Burmese) I had at least 25 extra kilograms (55lbs) of joy around my midsection. This labelled me as clinically obese. I wasn’t happy and wanted it gone. So I did what any self respecting nerd would do: I started looking for answers on the internet!

Eventually I found a blog post advocating the paleolithic diet. I was intrigued and bought the suggested book. I went on a strict diet, ate only meat and vegetables, avoided bread, potatoes, rice and pasta and lost 10kg in 3 months. Then the progress stopped, most likely due to my affair with Belgian beers and French wines at the time. I tried being strict with the diet again, but progress remained flat.

I wobbled between 100 and 104 kg for the next 3 years. I tried a lot of things: going regularly to the gym, eating and drinking less, structuring my meals, eating small portions multiple times per day, running in the morning, running in the evening, eating a large breakfast, not eating breakfast at all, daily pushups, colder showers, various supplements and anything else I could find. Nothing sticked and my weight remained the same. It didn’t help that I refused to be too strict and wanted to enjoy life with an occasional beer or wine or two.

In October 2013 things finally started to change. As part of my effort to become productive I started doing 15 minutes of exercise every day — either weightlifting and crunches at home or going for a 5k run. The sheer consistency in my routine made me gain muscle, lose weight and feel better, but progress was slow. I did get under 100kg for the first time in years, though.

On the 2nd of January 2014 I weighed 99.2kg. Then I started doing one thing differently.

I started fasting one day per week.

As a result my weight plummeted. I lost 10kg in four months and have kept it off since then.

Most of the downward spikes on the graph above happened directly after the fasting day. The two horizontal lines (beginning of March and end of April) represent week long unhealthy vacations. Even then I got back on track after just a few weeks of recovery.

I originally planned to fast just once to see if I could go a day without eating. The idea came from the book “Man 2.0 — Engineering the Alpha”, which I read a few months before and where intermittent fasting was highly praised. Check it out or read this blog post for a nice summary of the method.

I allowed myself one cup of tea with honey in the evening and as much water, tea and coffee as I wanted. I knew it was impossible to starve, as I ate a lot the day before. Still the idea of going for 24 hours without any food seemed alien at first. Was I going to be okay, I wondered.

Half way through the day I started craving for food. As I couldn’t eat anything I had to suck it up. It was hard at first, but when I started listening to my body I noticed something was out of place. The cravings didn’t come from my stomach. They were not cravings from hunger, but from something else. Was it boredom? The expectation of food at a certain hour? I don’t know. As the day crawled on the feeling diminished and I kept on working. Surprisingly I didn’t feel hungry in the evening.

That one cup of tea in the evening was intense. Even though I didn’t feel my mental capability lessen throughout the day, this one spoon of honey gave me clarity I hadn’t experienced often. In my food log I wrote: “I feel very good and alert, as if some blockage was lifted”

The next day I was a lot lighter and felt healthier. My stomach was not as bloated as it normally was. I felt real hunger for the first time in years. It felt different from the cravings the day before. I felt like I had learned to control my appetite and crave food only when I was actually hungry again. It felt liberating.

I decided to make this a weekly thing.

I also kept up the habit of doing some exercise every day. While it certainly helps with weight loss, it alone can’t explain the sudden progress, as I was already doing it for 3 months before with limited results.

- — -

There are thousands of weight loss programs out there, each of which promise amazing results for following a strict diet and exercise regimen. While people continue to lose weight with such programs, there’s something an order of magnitude better — learning to listen to your body and doing what it tells you. Unfortunately most people can’t hear themselves. Our antennae are out of tune and we hear a lot of noise, e.g. hunger when we’re bored or laziness when we need to exercise. We need to get the system in tune again.

For me, fasting one day a week does just that. It tunes my mind to the station of my body. It makes me feel real hunger and lets me differentiate it from other cravings. It resets my frame of reference and makes me limit my food intake on non-fasting days. If I can manage 24h without any food, then I can surely resist eating too much on a normal day, especially with all the fat that I have stored away.

The flip side is that if I eat or drink too much in the weekend, I know I have the Monday to reset my system and flush away the excess food. In fact, some people recommend an all-you-can-eat cheat day just before the fasting day:

Remember, dieting causes leptin levels to drop, which slows down fat loss; strategically overfeeding boosts leptin levels back up, increasing the rate of fat loss. Putting a fast day after a cheat day, therefore, does two things: 1. Prevents any fat gain from the caloric spillover of eating, oh, we dunno, 14,000 calories worth of ice cream by creating an immediate deficit 2. Prevents stagnated fat loss, allowing the hormonal benefit from the fast to proceed uninterrupted More than anything, though, this is just a practical approach created to alleviate discomfort. — Man 2.0 Engineering the Alpha, chapter 10

On a more metaphysical level, fasting once per week makes me feel more primal. These days we’re used to an unlimited 24/7 access to food. We eat when we’re bored. We stuff ourselves because there was too much on the plate to begin with. Back in the savannah we didn’t have a McDonalds on every corner and our ancestors went days without eating. Fasting one day a week is my way of getting back in touch with the core of the human experience. It makes me feel more alive.

- — -

And that is why I don’t eat on Mondays. Skipping food one day a week resets my caloric expectations, allows me to eat more in the weekend, tunes my mind to the signals of my body and just flat out helps me lose weight.

Obviously fasting one day per week is not an excuse to be unhealthy on the other days. I still try to adhere to a low carb diet, eating mainly meat and vegetables and severely limiting my intake of bread, pasta, rice and potatoes. That said, I’ll occasionally have a burger with fries and/or an ice cream, even on non-cheat days. I also go running a lot, as I plan to run my first marathon in 12 weeks. All of this keeps my weight in check, but without the ~2000 kcal deficit from fasting, it wouldn’t be enough to consistently make me lighter.

Whatever your weight loss goals, I can highly recommend giving intermittent fasting a try. Commit to trying it for just one day. Make it a challenge to see if you can go a full day without eating. What do you have to lose? Even if you’re already lean, adding fasting to your regimen can help you lose those last few percentages of bodyfat.

Choose one day in the next 7 days, mark it in your calendar and then don’t eat that day. If you can’t choose, pick tomorrow. Keep a log of how you feel. Notice your cravings and emotions. Drink a lot of water and as much tea and coffee as you want. I let myself drink one cup of tea with honey in the evening, you of course are free to come up with your own rules.

A normal healthy adult should not have any problems when fasting for 24 hours. That said, if you have any doubt, please consult your physician and read this blog post before starting. Especially if you have any special conditions, such as diabetes. Also, it is not recommended to fast more than one day per week.

If you try it out, I’d love to hear your experience. If you have any questions, write them in the comments and I’ll do my best to answer them.

Mark a day in your calendar now and enjoy the challenge!

Archived comments from when the blog was self hosted: