Writing for Aeon Magazine, S Abbas Raza and his wife decided to fast for one week. What ensued was a rollercoaster of boredom, increased energy, and diminished mental ability.

First of all, every single one of the seven days felt exactly the same: mornings were completely fine and I felt pretty much as I normally do until about lunchtime. I tried to pack in any work, especially work that required mental concentration, into this period of each day. After midday, I became a little fidgety and found it hard to concentrate on anything. I had much more than usual amounts of physical energy and did all kinds of household chores happily, such as defrosting and cleaning the refrigerator one afternoon (anyone who knows me will testify that this is highly unusual behaviour). But my mind flitted from one thing to the next, and my reactions were slowed down very noticeably by evening. If my wife asked me a question, it took about five seconds for it to register and another five before I could formulate and deliver a reply. In fact, I became decidedly cognitively impaired: one day after taking a shower and shaving, I applied aftershave lotion to my face and noticed that it didn’t have the mild sting it usually does. That is when I realised I had not actually shaved. I just thought I had.

A thoughtful conclusion: meals provide the much-needed punctuation throughout the day:

In fact, the biggest surprise was just how much more time we had on our hands. I was struck by how much of the day I normally spend attending to my digestive needs: thinking about what I would have for lunch or dinner; shopping for groceries (which we do almost daily); cooking — in my case, elaborate Pakistani meals most evenings; then actually eating, washing dishes, cleaning up, even moving one’s bowels. Eliminating the simple act of eating frees up much more time than you’d think. In addition to the couple of hours of daily exercise we kept up throughout, we took long walks in the mountains (we live in the Alps), did crosswords (rather slowly), surfed the net and fooled around on Facebook, and we still always had more time to fill. I realised that meals provide needed punctuation to the day, and without them our days seemed strangely lacking in structure.

It was an interesting experiment, but a fair warning: don’t try this at home.

I’ve done intermittent fasting before (for one day at a time), and I agree that one’s energy can (surprisingly) spike; however, I also became more mentally sluggish.