<p>One thing worth pointing out as a very terse hint of an answer: we all know that activation of the sympathetic nervous system is often referred to as the "fight-or-flight response," but parasympathetic nervous system (PNS) activation is less commonly known as the "rest-and-digest" response...though this does appear on <a href="https://en.wikipedia.org/wiki/Parasympathetic_nervous_system" rel="nofollow noreferrer">Wikipedia's PNS page</a>. Eating (or maybe just having fresh food in the early parts of one's gastrointestinal tract; I'm not sure) activates the PNS, which itself has soporific effects.</p>

<p>Also, a separate quote <a href="http://www.hypoglycemia.asn.au/2011/the-biochemistry-of-insomnia/" rel="nofollow noreferrer">from the Hypoglycemic Health Association</a> relating starvation to adrenaline production [emphasis added]:</p>

<blockquote>
  <p>When the brain is threatened with energy <strong>starvation</strong> it will send a hormonal message to the <a href="http://www.wisegeek.com/what-are-the-adrenal-glands.htm" rel="nofollow noreferrer">adrenal glands</a> to <strong>pour adrenaline into the system</strong>. Adrenaline is a hormone that converts <a href="http://www.answers.com/topic/glycogen" rel="nofollow noreferrer">glycogen</a> – strings of glucose molecules stored in the body – back into glucose, so as to feed the brain again. (See <a href="http://curezone.com/upload/PDF/Articles/jurplesman/Adrenaline_Trigger.jpg" rel="nofollow noreferrer">image</a>). But <strong>abnormal adrenaline</strong> secretion during the night can also cause <strong>insomnia</strong> and nightmares...</p>
  
  <p>If we are able to supply the body with all the nutrients, enzymes, coenzymes, vitamins and minerals, it will have all the ingredients to synthesize the necessary neurotransmitters and hormones that can make us feel happy and content when we should. A natural diet should provide us with all the components to build the necessary serotonin and melatonin to enable us to sleep.</p>
</blockquote>

<p>This is from "<a href="http://www.hypoglycemia.asn.au/2011/the-biochemistry-of-insomnia/" rel="nofollow noreferrer">The Biochemistry of Insomnia</a>," which may interest you more broadly, but I think I've quoted most of the content that pertains directly to diet here.</p>

<p><strong>Edit:</strong> BTW, you might also find this question of interest (I've answered it somewhat similarly):<br><a href="https://cogsci.stackexchange.com/q/5263/4086">The effect of proper food intake on emotions and brain function</a></p>

CC BY-SA 3.0
2014-01-28T07:36:33.867Z
2014-01-29T08:33:57.883Z
2017-04-13T12:56:16.467Z
Nick Stauner
<p>Yesterday I started a new diet using intermittent fasting. For this reason I only ate one meal all day. I was pretty surprised how well I passed that day: I studied a lot, did some sports and fulfilled several programming exercises from university. After sports I had my first meal. Overall—a great day without any side effects from the intermittent fasting.</p>

<p>However, at 11 PM I went to bed. There I realized that I was not tired. So I read a book. One hour passed—still no feeling of fatigue. So, I thought, some push ups will make me tired. Nope, the push-ups did not work. It was already 1 AM, and I had to get up early. I decided to use my strongest means, which I only use before big exams: a glass of brandy. No effect! Meditation—nope. After that, 30 minutes of running outside in the cold—again, no effect. At 4 AM I decided to get up and study. </p>

<p>A weird experience. I know that I lack sleep; nevertheless, I can study and concentrate.</p>

<p>I Googled the keywords <em>fastening</em> and <em>sleeplessness</em>. Then I realized that it is a common pattern that some people sleep less during fasting.</p>

<p><strong>Why is fasting related to insomnia?</strong></p>

CC BY-SA 3.0
2018-03-19T16:33:59.800Z
I used to be a bit of a gym rat. I adopted intermittent fasting; Eat for hrs then fast for 16 (including sleep). In practical terms this meant I got into a habit of stopping eating at 4pm. I had major sleep problems emerge but I did not connect them to how I ate. The past year, my sleep declined to 5hrs a night, the past month 4hrs - I had intermittent insomnia. I could not get back to sleep for 2 or 3 hours and the poor sleep after I woke was more like intermittent drowsing. Fixed this with a banana milkshake and 1/4 of a grated nutmeg at 8pm with 100g of milk and cereal (16g of sugar). Only
muscleriot
CC BY-SA 3.0
2018-03-19T19:27:21.830Z
mod addition (continued comment from @muscleriot): ...*been a few days so far but the difference has been dramatic. I use a Sleep Monitor and even my deep sleep has increased to over 2hrs of my now 6hr sleep.*
AliceD
<neuroscience><sleep>
How is fasting related to insomnia?
Jon
# How is fasting related to insomnia?

(Asked by: username_0 on 2014-01-28)

Yesterday I started a new diet using intermittent fasting. For this reason I only ate one meal all day. I was pretty surprised how well I passed that day: I studied a lot, did some sports and fulfilled several programming exercises from university. After sports I had my first meal. Overall—a great day without any side effects from the intermittent fasting.

However, at 11 PM I went to bed. There I realized that I was not tired. So I read a book. One hour passed—still no feeling of fatigue. So, I thought, some push ups will make me tired. Nope, the push-ups did not work. It was already 1 AM, and I had to get up early. I decided to use my strongest means, which I only use before big exams: a glass of brandy. No effect! Meditation—nope. After that, 30 minutes of running outside in the cold—again, no effect. At 4 AM I decided to get up and study.

A weird experience. I know that I lack sleep; nevertheless, I can study and concentrate.

I Googled the keywords *fastening* and *sleeplessness*. Then I realized that it is a common pattern that some people sleep less during fasting.

**Why is fasting related to insomnia?**

**Tags:** neuroscience, sleep

> **Comments:**
> **username_1**: I used to be a bit of a gym rat. I adopted intermittent fasting; Eat for hrs then fast for 16 (including sleep). In practical terms this meant I got into a habit of stopping eating at 4pm. I had major sleep problems emerge but I did not connect them to how I ate. The past year, my sleep declined to 5hrs a night, the past month 4hrs - I had intermittent insomnia. I could not get back to sleep for 2 or 3 hours and the poor sleep after I woke was more like intermittent drowsing. Fixed this with a banana milkshake and 1/4 of a grated nutmeg at 8pm with 100g of milk and cereal (16g of sugar). Only  
> **username_2**: mod addition (continued comment from @username_1): ...*been a few days so far but the difference has been dramatic. I use a Sleep Monitor and even my deep sleep has increased to over 2hrs of my now 6hr sleep.*  

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## 1 answers

### Answer by username_3 on 2014-01-28. Score: 9

One thing worth pointing out as a very terse hint of an answer: we all know that activation of the sympathetic nervous system is often referred to as the "fight-or-flight response," but parasympathetic nervous system (PNS) activation is less commonly known as the "rest-and-digest" response...though this does appear on [Wikipedia's PNS page](https://en.wikipedia.org/wiki/Parasympathetic_nervous_system). Eating (or maybe just having fresh food in the early parts of one's gastrointestinal tract; I'm not sure) activates the PNS, which itself has soporific effects.

Also, a separate quote [from the Hypoglycemic Health Association](http://www.hypoglycemia.asn.au/2011/the-biochemistry-of-insomnia/) relating starvation to adrenaline production [emphasis added]:

> When the brain is threatened with energy **starvation** it will send a hormonal message to the [adrenal glands](http://www.wisegeek.com/what-are-the-adrenal-glands.htm) to **pour adrenaline into the system**. Adrenaline is a hormone that converts [glycogen](http://www.answers.com/topic/glycogen) – strings of glucose molecules stored in the body – back into glucose, so as to feed the brain again. (See [image](http://curezone.com/upload/PDF/Articles/jurplesman/Adrenaline_Trigger.jpg)). But **abnormal adrenaline** secretion during the night can also cause **insomnia** and nightmares...
>
> If we are able to supply the body with all the nutrients, enzymes, coenzymes, vitamins and minerals, it will have all the ingredients to synthesize the necessary neurotransmitters and hormones that can make us feel happy and content when we should. A natural diet should provide us with all the components to build the necessary serotonin and melatonin to enable us to sleep.

This is from "[The Biochemistry of Insomnia](http://www.hypoglycemia.asn.au/2011/the-biochemistry-of-insomnia/)," which may interest you more broadly, but I think I've quoted most of the content that pertains directly to diet here.

**Edit:** BTW, you might also find this question of interest (I've answered it somewhat similarly):  
[The effect of proper food intake on emotions and brain function](https://cogsci.stackexchange.com/q/5263/4086)


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