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How does intermittent fasting affect sleep

Updated: May 22, 2023


Image of a clock with food instead of numbers, which justifies the article title of "How does intermittent fasting affect sleep"


Have you ever gone for hours without eating? I'm sure most of us have tried intermittent fasting, knowingly or unknowingly, at some point in our lives. For instance, when you get a good eight-hour sleep and go on a little longer without food after waking up, you actually end up doing intermittent fasting.



So What Exactly is Intermittent Fasting?


Intermittent fasting is an eating pattern that alternates between periods of eating and fasting. Unlike other diet plans that focus on restricting your calorie intake or suggest you eat only specific kinds of foods, intermittent fasting focuses on when to eat and how long to fast. During your fast, you're allowed to drink water, coffee or other non-calorie-containing drinks but refrain from consuming anything that has more than five calories in them.


In this write-up, we will discuss about intermittent fasting and how it can affect your sleep


The Various Types of Intermittent Fasting


There are various methods of intermittent fasting. Some of the most popular ones are:

  • The 16/8 Method: This is by far the most popular way of intermittent fasting. You fast for 16 hours with a window of 8 hours for your meals. This method feels comparatively more effortless than the others as most people fast while sleeping. You can have an early dinner at 7 pm and have lunch at around 12 pm by skipping breakfast the next day. You may also start with the 14/10 Method, wherein you can fast for 14 hours and have a 10-hour window for eating. If you're just a beginner, you can start by fasting for 12 hours a day.

  • Eat-Stop-Eat Method: This method is also known as the 24-hour fast. Herein you fast for a full 24 hours window. It's usually done once or twice a week.

  • Twice-a-week Method/ 5:2 Diet: In this approach, you fast for two days a week in a way that your calorie intake is just 500 KCal per day. You can select these days as per your comfort and convenience and make sure that they are not consecutive.

  • Alternate day fasting: As the name suggests, you fast every alternate day. You can either keep your calorie intake 500 or 0 on your fasting days, depending upon your comfort and choice. Alternate day fasting helps in weight loss as well as in maintaining heart health.



How to Start Your Journey Toward Intermittent Fasting?


Intermittent fasting is an excellent way to curb midnight cravings and get in shape. It also has several cardiometabolic benefits that can be beneficial in the long run. As such, there are no specific risks of intermittent fasting, but it should be avoided if you're pregnant, nursing a baby, or are at risk for hypoglycemia (low blood sugar levels) since it might cause some adverse effects.


If you're new to intermittent fasting, you can start your journey by taking baby steps. The best way to do intermittent fasting is to incorporate your sleep hours into the fasting period.

  • You can start eating your dinner at 7 pm and have your breakfast at 7 am.

  • Out of these 12 hours, you'll only have to be hungry for 4 hours if you're getting an 8-hour sleep, which seems pretty doable.

  • Try to have protein and fiber-rich food before fasting so that it keeps you full for longer.

  • Keep yourself hydrated.

  • After getting used to fasting for 12 hours, you can start increasing your fasting window by 30 minutes or an hour each day and reach the 14/10 or 16/8 method.


Some Health Benefits of Intermittent Fasting


Science has revealed some fantastic benefits of intermittent fasting. Here are some of the health benefits of intermittent fasting:

  • Aids in Weight Loss: Intermittent fasting has been used as a popular way of losing weight. Research has shown intermittent fasting to be one of the effective ways to lose weight.

  • Improves Metabolic Health: Studies have shown that Intermittent fasting helps improve your cardiometabolic health. Metabolic Health is reflected through parameters like insulin sensitivity, blood pressure, oxidative stress, etc. It refers to how well our body uses and metabolises energy. Intermittent fasting helps lower blood cholesterol, thus maintaining cardiovascular health.

  • Helps you Live Longer: Studies in mice suggest that intermittent fasting might help you live longer. Several studies show that intermittent fasting might actually increase longevity.

  • Protects against diseases like Type 2 Diabetes, Cancer, Heart diseases, etc.


Since most of us fast while sleeping, it's important to understand the relationship between intermittent fasting and sleep. Let's look at the effects of sleeping on intermittent fasting.



Intermittent Fasting and Sleep


Studies suggest that intermittent fasting helps restore your circadian rhythm, thus improving the quality of your sleep. Your circadian rhythm is the natural clock inside your body that regulates your sleep-wake cycle. It does so by increasing the levels of a neurotransmitter called Orexin-A during daytime which is responsible for causing alertness in people who fast. As the night approaches, the levels of Orexin-A start falling, thus ensuring a relaxed and sound sleep.


Your body releases growth hormones when you’re asleep. These growth hormones help burn fat, restore muscles and repair the body at cellular levels. Intermittent fasting increases the secretion of growth hormones, due to which people who fast wake up feeling more refreshed.


Intermittent fasting has been shown to improve sleep in terms of better sleep quality, better mood, and better focus during the day in as little as one week.


Intermittent fasting and sleep can go hand in hand when meals are taken at the correct time. If you eat at odd hours that are too close to bedtime, your body's temperature might increase, which will keep you from falling asleep. If you eat a heavy meal right before bedtime, you might encounter an upset stomach which will again make it harder for you to sleep, thus disrupting your sleep quality.



Wrapping Up: Intermittent Fasting and Good Sleep


You can incorporate intermittent fasting into your lifestyle by prolonging the time gap between dinner and breakfast. Intermittent fasting has several benefits. It can help you lose weight, protect against diseases, and increase longevity; however, do remember that it's not for everyone. Taking some necessary measures as mentioned here might help you improve the quality of your sleep.

  1. Be consistent with your eating schedule

  2. Don't starve yourself before going to bed

  3. Eat nutrient-dense food

  4. Keep yourself hydrated

If you’ve always wanted to try intermittent fasting but were too hesitant to take the plunge, consider this post as your cue. You deserve the chance to live healthy life. Fasting can be first step towards your goal.

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