Some thoughts prompted by fasting

I haven’t eaten anything in 11 days. This is the fourth time I’ve done a long fast. The longest one was 30 days.

What does this have to do with Self-realization? Trust me, I’ll get to that.

It’s surprisingly easy to fast. After the third day, there’s no hunger. Our bodies are designed to go long periods of time without food, but most of us never realize this because we give up during the first three days.

Water is something else. We die very fast without water. There are people who try to go without water. This is insane.

When I did my first fast, I was astonished to discover that I felt almost completely normal, without any hunger, for the first two or three weeks. It was as if a superpower had been hidden inside me all my life, the ability to go without eating for weeks without discomfort, and I had never known.

After the first three days, there is no hunger during a long fast, but there is an obsession with food. Right now my thoughts are mostly about food. I have never had much interest in cooking, but every time I fast, I watch hundreds of cooking videos. Yesterday I went to the supermarket twice and walked around for hours examining all sorts of food that I don’t usually eat. I spent $80 on spices and exotic grains like mote de cuzco (giant Peruvian nixtamalized maize). I bought three kinds of Italian rice for making risotto even though I’ve never made risotto in my life.

All this food goes on shelves in the kitchen. I have no interest in eating it. I’m not the least bit hungry. But I keep thinking about food and looking at it on the Internet and going to the store to buy it.

I’ve talked to several other people who have done long fasts and they tell me their experience was the same: no hunger, but an overpowering interest in food.

Isn’t this fascinating? Why do we feel like this?

I think we feel like this because our thoughts and urges and desires are created by our brains, and our brains have been designed by natural selection to keep us alive. In other words, we feel this way because of evolution. It’s a biological thing.

For millions of years, our ancestors frequently experienced famines, periods when there was no food. During those periods our ancestors starved. Natural selection built something like “computer programs” into our ancestors’ bodies that got turned on during those times to help keep them alive. Those programs are still inside us today, and we can turn them on by fasting.

One of those programs changes our bodies’ physiology by switching from a glucose-based metabolism to a ketone-based metabolism. Other programs change our thoughts and urges. One of these programs makes us intensely interested in food.

It makes perfect sense that natural selection would program us to be intensely interested in food when we’re starving. And not just interested in food, but interested in food that we’ve never eaten before. I didn’t just buy $80 worth of food yesterday. I bought things like mote de Cuzco (giant nixtamalized Peruvian corn). I’ve never eaten that before or even heard of it.

Why am I behaving this way? Why am I scouring the supermarket for exotic foods I’ve never eaten before?

Our ancestors had no stores or farms. They lived out in the open, in forests and prairies and wetlands, and got their food like all animals do, by scavenging growing plants and hunting and eating insects. During a famine, when their customary foods were nowhere to be found, it was to their advantage to search the local area intensively and try to find something edible, something they had never eaten before.

That’s what my brain is making me do: it’s making me search my local forest (which is a supermarket) to try to find foods I’ve never eaten before.

How does my brain make me do things? How does it control my behavior?

It makes me do things by giving me desires and rewarding me with pleasure when I do what it commands.

It stops me from doing things by making them scary or disgusting and “rewarding” me with pain and discomfort when I do them.

Our behavior is controlled by a sort of internal carrot and stick mechanism. Desires and pleasure are the carrots; fear, disgust, and pain are the sticks.

A simple example is thirst. When the body gets low on water, the brain makes us feel thirsty. That feeling makes us drink. The brain creates the feeling of thirst in order to increase our blood volume. The feeling of thirst is part of the body’s physiological regulatory mechanism.

What does my desire to spend hours at the supermarket have to do with Self-realization? It shows that our urges and feelings are mechanical things. They are like computer programs. They are not us.

Most people define themselves partly in terms of what they enjoy. On dating websites, people often say things like, “I like heavy metal, working out in the gym, dancing, and hiking.” To some extent these statements are practical, because people with common interests find it easier to do things together, but at the same time, people really believe they are what they like. They think their interests, what they enjoy, are them.

The point of this post is that our urges and desires are mechanical things.

Right now, I like shopping for food and watching cooking videos.

But that’s not me. My “like” is a sort of computer program.

That doesn’t mean it’s bad. The urge I’ve discussed in this post, the obsessive interest in food that occurs during starvation, is a very good thing. It was created by natural selection — that is to say, by God* — to keep us alive. The beauty and perfection of that mechanical system is as splendid and beautiful and awesome as anything we experience.

But it’s not us. That urge is not us.


*Many people believe that the theory of natural selection denies that God is the Creator, therefore the theory is atheistic. In my opinion this belief is naive and foolish. People hold this belief because they imagine that God is an extremely talented person who sat at a drafting board and designed all the plants and animals. But God is not a person, and God didn’t create things in the way that humans create things. God is the essential true nature of reality, and luckily for us, that essential true nature is love. There’s no contradiction between natural selection and God. Natural selection is the way God made plants and animals. There only seems to be a contradiction if you have an extremely limited notion of God.

12 thoughts to “Some thoughts prompted by fasting”

  1. I really liked this, Rob. Having spent many of the first 20 something years of my life tormented by the content of my thoughts, it was so refreshing and joyful to intuit that thoughts, beliefs, desires are not what we are. You have inspired me to want to fast… 🙂

    1. Thanks Charlie. I realized yesterday that I haven’t felt a single twinge from the arthritis in my hands in days. The fast is helping with that.

  2. Very sound theory! My behavior and lack of hunger paralleled yours when I fasted for 8 days. But I hadn’t paid attention to my “search for novel food” issue. But it sounds so true!
    By the way, you might want to look into the “Potato Hack” for arthritis relief (and some other) via dietary restriction, if you haven’t already. It works in many people, and might be worth a try.

    1. And this post is worth keeping even just for the clear explanation of the non-contradiction between theory of evolution and God which I am often not able to express so clearly.

    1. I ended up fasting for 24 days, longer than I expected, because I noticed that my eyesight was improving (I have cataracts and have been putting off surgery) and I wanted as much improvement as possible. Lately I’ve been eating a lot of cherries and Thai curries. I’ve gradually been cooking and eating the exotic foods I bought during the fast. A few days ago I cooked Peruvian unhulled roasted barley. Even after simmering it for two hours the hull was like wood, making me think it’s meant to be used only for making tea not eating. What are you eating (not eating) these days?

      1. Thanks for the quick reply. How is your eyesight now that you are eating again?

        I just had potatoes and onions fried in olive oil and two eggs with cheese. I probably won’t need to eat again until tonight and it will be something light, like a bowl of cereal. I also sip on one cup of coffee with half and half and raw sugar throughout the day.

        1. I think the eyesight improvements remained after I started eating again but it’s hard to be sure. I’m trying n-acetylcarnosine for cataracts now but I’ll probably have to wait a few months before I can tell if it works.

          Your potatoes and onions in olive oil remind me that I was looking forward to eating a Spanish tortilla while I was fasting. I should make one!

  3. HI Freddie:

    Love your site. Now, about your sight:

    I understand the impulse behind putting off the surgery.


    I first wore glasses at age 7, and continued until age 64. The eyes started getting cloudy around age 59, they told me to wait, and at 64, got the surgery.


    I can see clearer than ever before in my life. No problems at all for far sights, $20 drugstore glasses for working at the computer.

    Strongly recommended. Hope it works out well for you.

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