20 hours without eating: Intermittent fasting part 2

Ed. note: This is part 2 of a series that was written after a day of trying intermittent fasting, or IF. As I explained in part 1, fasting is not starvation, and is a discipline that has been practiced for thousands of years by cultures around the globe. Here’s how it went.

On Saturday I decided that it was the right time to try intermittent fasting (IF). As I explained in part 1 (“20 hours without eating: the intermittent fasting experiment“), IF is essentially giving your body a break from food for a set period of time, and then eating the calories and nutrients you need during a specific window. If you are trying to lose weight, the key is during your eating times you take in the appropriate nutrients while maintaining a reasonable and healthy caloric deficit.

In my case I chose to fast for 20 hours, starting at 9PM the previous evening and having only water (and a cup of coffee) until 5PM the next day. I also asked my wife to make dinner for the family to be ready at 5 or so, just so that when the fast was over I could actually eat something substantial and more importantly, planned (in my mind, no plan might equal disaster food-wise). I also asked her to make something extra tasty ;).

Of course, I wasn’t sure if I could even make it that long mentally. Could I actually last 20 hours without giving in to cravings of, well, anything? How would I do physically and more importantly, emotionally? I decided to go for it, knowing that if things got too out of hand I could always stop. The results were pretty surprising.

Play by play experience of 20 hours of intermittent fasting

These are some of the highlights of how I felt throughout the day. To be fair, I did write this after the fact, but this is what I remember.

9AM: The morning went well, but I discovered right off that bat that the smell of toast makes me instantly hungry. Even burnt toast, which is what happened when I was making some toast for my 5-year old. However I resisted the urge to make a piece for myself and moved on. Small victory, but victory nonetheless. Other than the momentary desire for buttered toast, hunger was no problem. Reasonable energy, and my head was on straight.

10AM: Stomach was definitely starting to grumble a bit, mostly stimulated by the breakfast we made available for the kids (papaya slices, apples, and whole grain toast). Emotionally I was doing OK with it; no desperation for food at all. But I also realized I needed to get busy with the day’s work to take my mind away from food.

11AM: Definitely starting to feel hungry. Oddly I had forgotten until this point that I was allowed to drink water, so I had a large glass and that instantly helped the hunger. Emotionally I was definitely starting to get grumpy, but to my surprise the water also helped with that almost instantly.

Noon: Hungry, but staying busy and drinking water. A little bit of sweating, but I believe it was more from the work I was doing than from blood sugar, though I could definitely feel some jitters from either the cup of coffee I had (first thing in the morning before I decided to fast), or from lack of food – truly not sure. Energy was good otherwise. The rationalization head games tried to take hold (“just one cracker?” kinds of thoughts), but I just kept moving and drinking water.

1-2PM: Similar to noon, but I remember clearly thinking a lot about the fact that I only had 4 hours to go until I could eat. Having a solid goal helped quite a bit. Energy was fine, and emotions had settled a little. No desperation feelings surprisingly.

3PM: Feeling a bit lightheaded once or twice. A little foggy mentally, but not bad (it could be that I was simply more focused on it – I’m probably foggy normally :) ). Energy was up however, and a perceived feeling of calmness was also very distinctly present. I had to run to the local home supply store to pick up a few things, and was able to navigate the checkout aisle with no interest at all in the junk food that normally tries to jump into my cart (another small victory).

4:00PM: Time for my run. Energy was excellent – I would go as far as to say abundant – and motivation was high considering I only had an hour to go before eating (I was definitely looking forward to that).

The run (4:15-5:15 or so): Before running I wondered if I would experience any physical effects from having not eaten all day. Cramping, lightheadedness, lack of energy? None of the above. In fact, the run went really well. I finished and did a handful of crunches and push-ups for good measure.

5:30PM: Time to eat. I gave myself a one hour window to eat for the evening so that I didn’t overdo it, and that seemed to work. I had promised myself that I could eat as much as I wanted at dinner as long as I started with a large salad. Fortunately my wife was prepared with a great salad of greens, dried cranberries, her excellent vinaigrette, a little blue cheese, and some chopped hazelnuts. Salad never tasted so good. And that was actually a good point – my lack of food all day really sharpened my enjoyment of the salad – I had two servings. After that, a family recipe of thick cut lean pork chops (from a local sustainable farmer) with vegetables was dinner, with a small glass of white wine and a large glass of water. Finally I had a cookie for dessert – and although this was refined sugar, it was a limited indulgence.

by 6:30, I was finished eating for the day, I was stuffed, and felt a strong sense of accomplishment.

Evening/Post-fast: On a normal eating day, by suppertime I am generally really, really tired. I sometimes feel like I could fall asleep at the table. Today it was the opposite. In fact, by 7:30 I had exceptional energy – possibly from the run, and possibly from the experiment – I can’t be sure. I did the dishes and was energized to write this post.

All in all a great day.

Takeaway on IF

This was certainly not easy, yet not nearly as difficult as I thought either – especially on the emotional front. Hunger was there without question, but the water really helped. A few mental tricks also worked (like keeping in mind that I could eat anything I wanted at 5, thinking about the positives of getting back in shape) to keep going. I was feeling so good by the end of the day that I considered doing it again the next day, but I would rather use it as an intermittent motivational tool rather than a daily routine at this point. Instead I’ll practice “clean” eating habits by focusing on whole foods for a few days – and then possibly another fast. We’ll see.


  • True sense of accomplishment: By the end it felt really, really good not only to demonstrate to myself that I had the willpower to do it, but it really kickstarted a week of healthful eating.
  • A distinct feeling of serenity late in the fast: This really surprised me, but was a tangible benefit. I felt as though I was flowing through the day rather than fighting my way through it.
  • Abundant energy: I have not felt that much energy in a while, particularly without caffeine being involved.
  • No ill effects on exercise: No cramping, great energy, and the will to keep running until my goal was reached.
  • Greater enjoyment of the foods I ate after the fast: The foods I ate tasted incredible, from the salad to the wine. The lack of food during the day I felt really sharpened my enjoyment of the meal. Granted, my wife’s meals are always excellent, but the fasting really accentuated her cooking (yes, that was a shameless suck-up. Never hurts. :) ).
  • Hydration was excellent. I estimate I drank easily 12 glasses of water, particularly with the run.
  • [Update: I had very little soreness from the run, which is a good sign. I also did a mild fast the next day, limiting my eating window from 2-6. I also successfully said no to pizza and cake on Sunday in favor of waiting for better food later – another victory.]


  • I will leave room for the possibility that it could have had some adverse effect on my metabolism, but I doubt it. Time will tell.
  • Required mental focus: It did require a fair bit of focus to make it through, but I would say no more than it does to prepare 6 meals for a single day (a common approach to healthful eating). I also think that it had a lot to do with trying to be very conscious of the experience to track how I was doing. I have a feeling that the next time will require much less mental energy having one under my belt.
  • Some occasional lightheadedness, and possibly a blood sugar low early in the day (not sure). On blood sugar however, if that was the case, I suspect that has more to do with my body expecting sugars (because I’ve trained it to expect excess sugar) than an actual need. More research however is in order.

A few things learned:

  • Do NOT work on your food journal while you’re fasting. I tried this for a few moments, and not only did it make me feel hungry, but I could feel the groundswell of emotion coming up. Yikes.
  • Set a goal: When fasting, use the simple strategy of reward when the fast is over. Know what time you are shooting for, as that marker will help pull you through.
  • Avoid food aromas that turn on your hunger switch if possible.
  • When you return to eating, take it slow. You might be inclined to scarf down your food, but don’t – it may make you feel ill.
  • Likewise, when you start eating for the day, make sure you are getting the nutrients you need.
  • Take natural supplements if that is right for you. In my case I’ve been taking whole food supplements from Whole Food Nation (thanks Robin), and I experienced no nausea or ill effects from taking them only with water, though your experience may be different.

Healthwise I also tend to think there is nothing wrong with occasional fasting. [Warning: Soapbox alert] In this country especially our food-obsessed pendulum really swings toward hyperfocus on eating in my opinion. The idea that the body needs to be fed all day long seems a little extreme to me, and says more about a culture of abundance than actual science (yes, them’s fightin’ words, I know). There are plenty of studies to prove either view; but for me, I don’t really want to be that food-focused with every aspect of life. Not to mention, obsessing over every crumb and calorie is an approach which for me has never worked.

Likewise I don’t subscribe to the “a calorie is a calorie” or “food as fuel” mentalities either. Food should be pleasurable, not just raw energy. It is one of the most meaningful ways that we communicate across cultures, and it says a lot about the spirit of a person and their home. When I eat a meal, I want to enjoy it thoroughly as a sensory experience that satisfies not only caloric or nutritional needs, but is a true experience in the pleasure of eating. And ultimately that is the mission of Almost Fit: figuring out how to enjoy food without it being to the detriment of health. Seems simple enough. :) [end Soapbox]

The bottom line? I loved it, and I’m definitely going to do it again between days of eating normally. I may also adopt a more moderate fasting style, where I limit my daily eating window to 6 hours. I’m not sure yet, but it sounds like another great experiment.

Oh and one last thing: What was the result weight-wise, considering my goal of losing 10 lbs this month? You’ll have to wait until the next post to find out.

Ed note: Thanks for reading Almost Fit. If you enjoyed this series, please consider sharing it with one of the buttons below.

And one more time with the Heavy disclaimer: Note that I am not a doctor, and this is not a recommendation as such. If intermittent fasting is something that interests you, you should do your research, talk to your doctor, etc. Fasting is certainly not for everyone, particularly people with known or underlying health conditions, eating disorders, and so forth, so use caution and think it through. Thanks again.