Last Updated on November 9, 2023 by Fasting Planet
You’ve decided to do your health a favor and fast. You have a lot of willpower, so the days aren’t an immense struggle for you. Then you try sleeping and toss and turn all night as your hunger pangs get seemingly worse. Why is it so hard to sleep while fasting?
It’s difficult to sleep during a fast because our cortisol and noradrenaline levels change during an intermittent fast, interrupting our sleep. Also, we’re hungry. It is worth it to be patient, though, as research has proven it may be possible to slightly increase sleep quality through fasting.
In this article, we will talk in much more detail about why shuteye is so hard to come by during an intermittent fast. We’ll also provide a few tips for finally getting some rest so you feel alert and ready to tackle your day.
Let’s begin!
Why Is It So Hard to Sleep When Fasting?
You climb into bed the first night of your fast, tired and hungry. You engage in your bedtime routine and wait for sleep to follow. It doesn’t happen. You lie there, still tired and hungry, and spend the next few hours tossing and turning. Maybe you doze for an hour or two before your alarm rudely goes off. Then it’s time for work.
Ugh. Why couldn’t you sleep last night? Let’s explore the factors more now.
Changing Levels of Cortisol and Noradrenaline
Dr. Jason Fung, the Diet Doctor, mentions that both our cortisol and noradrenaline levels increase during an intermittent fast, keeping us awake. Many people know of cortisol as the hormone that plays a role in depression, but it does a lot more than that.
Cortisol levels will increase on any given night after we slip away to dreamland. Yes, that’s even when we’re not fasting. By the time we’re ready to wake up, the hormone levels have reached their high for the night.
Several studies have found that when you have sleeping difficulties and interruptions, your cortisol levels also go up. These can be little sleep interruptions too and it still happens. If you don’t sleep at all, also known as insomnia, then you’ll have 24 hours of elevated cortisol levels to deal with. That makes sleeping the next night very difficult.
Then there’s noradrenaline, or norepinephrine. This body chemical floods our body when we’re under a lot of stress. Our blood pressure goes up and so does our heart rate. It should come as no surprise then that, in a 2010 study in Biochemical Pharmacology, the researchers came to this conclusion: “The neurotransmitter norepinephrine…through its involvement in the ascending arousal system, impacts the efficacy of many wake-and sleep-promoting medications.”
New Routine
Let’s say you get a new job that now requires you to go to bed and wake up two hours earlier than you did before. Do you think you’ll fall right to sleep that first night if you crawl into bed two hours ahead of your old schedule? No.
Our bodies have a circadian rhythm or an internal clock. This generally tells us when to wake up and when to go to sleep. While outside factors can influence it, our internal clock remains generally the same. Well, until we start a new routine. Even something as subtle as shifting your sleep/wake time by two hours will take some getting used to.
When you fast, your body is making a huge adjustment. Sleep won’t come easily for the first few nights.
Hunger
During the day, it’s easy enough to forget about your fast. You’re at work, and then you go home and clean up around the house and maybe engage in some light exercise. Even activities like watching TV or a movie can distract you from your reality: that you’re hungry.
When you’re in bed at night, all those distractions disappear. You’re left alone with your thoughts and your grumbling stomach. It becomes very hard to focus on anything but your hunger pangs, which in turn keeps you awake longer.
Does It Become Easier to Sleep on a Fast?
The first nights of sleeping on a fast is hell. You barely get any rest. You hope your exhaustion will make the second night better, but remember how your cortisol increases when you have a night of insomnia. Thus, it’s not very likely you’ll sleep well tonight, either.
Is there a silver lining in your future? It depends on which study you look at.
This data from 2004 through the Japanese Society of Sleep Research studied those who fasted for the holiday Ramadan. The data found the respondents had less Stage R sleep, where the R stands for rapid eye movement or REM sleep. This is a deeper and more restful form of sleep. Before that, a person is in non-REM or NREM sleep. This has three stages:
- N1 sleep lasts for 10 minutes or fewer. You’re in a very light state of sleep because you just drifted off. Almost anything can wake you up at this point.
- N2 sleep goes on for up to an hour after N1 sleep. Delta or slow-wave brain activity may occur, as does muscle relaxation.
- N3 sleep occurs for 40 minutes. It’s the last stage before REM sleep. It’s deep, but not as deep as REM.
When you don’t get as much REM sleep then, you won’t feel as rested when you wake up the next morning. The study also noticed that Ramadan fasters had less sleep latency time. This means they didn’t fall asleep as quickly.
Is that supposed to be good news? Well no, not exactly. Here’s a more promising study. It comes from a 2003 report in the Annals of Nutrition and Metabolism. Those researchers found that by doing short fasts of a week or less, you could sleep better. To reach that conclusion, the scientists reviewed how many times the respondents moved their legs as well as how many times they woke up and entered REM throughout any given night of sleeping. The respondents had fewer leg movements, fewer wakeups, and more REM sleep (noted as a “non-significant increase”).
How to Get Some Shuteye During a Fast
You’ve spent at least two nights awake because of your fast. It’s imperative you sleep tonight. Do you have to quit fasting altogether to finally get some rest? Not exactly. Just follow these tips instead.
- Try melatonin supplements. This hormone, which comes from our pineal gland, is partially responsible for determining when we feel tired and when we wake up. While it doesn’t work for everyone, you could use a supplement to induce sleepiness.
- Don’t make it hard to fall asleep. Avoid using your smartphone, tablet, or any other screened device right before bed. The blue light from these devices can mess up our circadian rhythm. Keep the room dark and maintain a temperature that’s comfortable for sleeping, which is anywhere from 60 to 67 degrees Fahrenheit.
- Go to bed only when you become truly tired. Dr. Fung personally recommends this method. Does it mean you only sleep for four hours? Maybe. Still, rather than wasting time tossing and turning, you get truly sleepy first. That might make it easier to fall asleep.
- Don’t drink caffeinated beverages like soda or coffee several hours before bed. Even chocolate can amp you up and make getting rest much more difficult.
- If you can eat as part of your fast, then schedule your mealtime early in the night.
Conclusion
Fasting has a host of health benefits, but sleeping when on a fast can be torturous. You can’t stop thinking of how hungry you feel. You also have a host of factors working against you, like increased cortisol and noradrenaline levels.
It is possible to sleep while fasting. Take melatonin supplements, watch what you eat and drink (if you can do either), and wait until you’re practically falling asleep in your seat to go to bed. Some studies say you could even sleep better on a fast!