Intermittent Fasting Experiment – Update after 5 Months

During the fasting periods, there really is no spoon. (Photo by alicepopkorn)

It's now been over five months since I started my intermittent fasting experiment, which means it's time for an update.

To recap, when I started in August, I went straight for the 24/24 version of intermittent fasting. That means I eat for 24 hours and then fast for 24 hours. I usually either start or stop eating at 4 PM, so every other day I miss breakfast and lunch and every other day I miss dinner. On the other hand, I don't really think in terms of "three warm meals per day" anymore, so breakfast, lunch & dinner have sort of lost their meaning.

This kind of fasting is also known as alternate-day feeding (or ADF) in a lot of the mouse and rat studies. That's a fitting term for rodents, because they don't have the same sleep pattern that humans do; that is, they don't sleep 8 hours per night and then stay awake for 16 hours. Instead, they sleep short periods throughout the day and night and eat when they feel like it.

In humans true alternate-day feeding is difficult, because the fast would begin at 12 o'clock in the night and you'd have to go for an entire day without food. With intermittent fasting, where you can break or begin the fast in the middle of the day, you get to eat at least something each day. This makes it much more convenient for humans but still retains all the health benefits of ADF.

The obvious question in most people's minds is probably "What about the hunger?" Well, in the beginning hunger was certainly an issue. Even though caloric restriction had been much more difficult due to constantly being hungry and having to count everything, my first fasting periods were still somewhat hard to get through.

I then tried green tea and black tea, both of which were moderately effective at reducing the feeling of hunger. The best thing, however, was coffee, which not only reduced hunger but also improved my concentration and mood. I now start each morning with a cup of coffee, and it definitely has helped a great deal. I also drink green and black tea throughout the day, but it's mostly for other health benefits.

As much I love coffee and tea, the most important thing has been time. During the course of this experiment I've noticed less and less hunger during the fasting periods. I assume it takes a while for the body to get used to the new situation, where it suddenly isn't constantly provided with energy. Nowadays, I rarely feel extremely hungry even in the last few hours of the fast. Sure, I have a great appetite when it's time to eat again, but I feel very energetic during the fast. I've now even been able to hit the gym during a fast, which seemed quite difficult during the first two months.

At first I thought I felt less hungry because I was sleeping a lot (9-10 hours per night) and thus spending less energy. When I reduced my sleep to seven hours, I noticed I felt no more hungry, even though I spent more time awake (and got much more things done). In fact, I don't think I've ever felt so energetic during the dark winter months while sleeping this little.

So if you're considering giving intermittent fasting a go but have doubts about the hunger issue, rest assured that it will get easier with time. You could always start easy and fast for 12 hours, then 13, 14, etc. until you get to 24 hours.

One thing fasting unfortunately doesn't seem to have changed is the immune system; some people have said they haven't been sick since they started intermittent fasting or caloric restriction, but I'm currently fighting the flu virus unsuccesfully. Just in time for the holidays, too. Oh well, you can't have it all, can you?

Merry Christmas to everyone reading this blog!