Beyond breathing air, the next most critical activities you do each day are eat, drink and sleep. Did you know that, even more than the types of foods you choose, the timing of when you eat and when you abstain from eating—known as fasting—can impact your sleep?
Read on to learn more about fasting, how fasting and sleep health are related, and why you might want to consider adjusting the timing of your eating to improve your sleep.
HISTORY OF FASTING
Fasting has become a popular topic in the last few decades as researchers dig deeper into the health benefits associated with restricting eating to specific time periods. However, the concept of fasting dates to ancient times—connected to both religious practices and political protests in addition to health considerations.
Fasting as a popular health practice has been reported as early as 5th Century B.C. when Greek physician Hippocrates recommended that his patients abstain from eating or drinking if they showed symptoms of certain illnesses. Meanwhile, researchers in the 19th century began evaluating how fasting impacted the body. By the 20th century, the health benefits of fasting for different periods began to be explored, primarily recommended for weight loss and treating convulsive disorders.
Today, researchers continue to explore the interconnection between the timing of when people eat and sleep, as well as their overall health and risk for disease.
TYPES OF FASTING
At its most basic level, fasting is the willful choice to abstain from taking in calories. The practice of fasting involves either entirely going without food and beverages that contain calories or taking in only minimal amounts of them for a specific time window that typically ranges from 12 hours to three weeks. The primary types of fasting include:
- Time Restricted Feeding (TRF)
- Intermittent Fasting (IF)
Time Restricted Feeding
Time Restricted Feeding (TRF), is the process of limiting eating and drinking calories to certain hours of the day. This process typically focuses on having the fasting period last 12 or more hours.
- 12-hour fast: The 12-hour fast restricts eating between the last meal of the day to the first meal of the following day. You begin and end your fast at essentially the same time—for example, 6:30 pm to 6:30 am. To be successful with TRF, it is best to try and not eat after dinner and keep a consistent nightly mealtime each day.
- 16/8 method: Because the health benefits are greater if the fasting period is longer, the 16/8 method is gaining popularity. This approach typically involves skipping breakfast, then restricting eating to an 8-hour window each day.
Intermittent Fasting (IF) involves periods during the week where you abstain from eating entirely. Two of the most popular IF methods are:
- Eat-stop-eat: This method offers a 24-hour cycle between eating and fasting—such as not eating between 6:00 pm one day to 6:00 pm the next day—followed by 24 hours of eating, with the fasting beginning again at 6:00 pm the next day.
- 5-2 fasting: This method involves restricting calories (usually about 500 total) on two non-consecutive days of the week, then eating normally the other 5 days.
POSSIBLE HEALTH BENEFITS OF FASTING
Research shows that fasting can:
- Improve insulin sensitivity
- Reduce inflammation
- Lower cholesterol (LDL)
- Protect against some cancers
- Improve brain health (protecting against conditions like Alzheimer’s disease)
Interestingly, each of these conditions is also related to your sleep health.
THE CONNECTION BETWEEN FASTING AND SLEEP
Before reading this article, you may not have realized that you already fast every day. Every night, when you go to bed, you begin fasting: you are not eating food or drinking beverages that contain calories during the period that you are asleep. This break from calories allows your body to slow the digestive process and direct that saved energy to growing, repairing, and rebuilding tissues in the digestive system and other areas of the body.
HOW EATING BEFORE BED IMPACTS SLEEP
The fuller your stomach is, the longer it takes for your body to process the food inside. If you eat right before going to bed, your body is not able to redirect all the desired energy to repair and restoration; instead, it uses some energy to digest the calories you ate or drank. Therefore, the National Institute of Diabetes and Digestive and Kidney Diseases recommends you stop eating food or consuming beverages with calories at least three hours prior to going to bed. There are a few reasons for this recommendation.
As noted, if you eat right before going to bed, your body is forced to apply energy to process the food you consumed. That means your body cannot focus primarily on repairing itself and rewiring the brain.
Second, when you lie down horizontally, you no longer have gravity keeping food in the digestive tract for processing. Instead, the contents of the stomach and the digestive juices can flow back up into the esophagus, causing heartburn, acid reflux, or other issues that can disrupt the quality of your sleep.
It is also recommended that you stay away from consuming alcohol before bedtime. While being intoxicated may allow you to fall asleep quickly, it can interfere with REM sleep and may result in other sleep disruptions as well.
All of that said, having a rumbling stomach can make it difficult to fall asleep. If you are truly hungry right before bedtime, you can first try drinking a glass of water and seeing if that adequately fills your stomach. While water has no calories, and you are still technically fasting, filling the space in your stomach may be enough to overcome the sensation of hunger that can disturb your sleep. If that is not enough, try to stay away from dairy, spicy foods, high sugar foods, and greasy foods as they each may lead to stomach distress during digestion. Pick something small and easy to digest that is carbohydrate-rich like a small serving of crackers or toast. These foods help trigger your body to release tryptophan into your bloodstream, which is associated with making you sleepy.
INCORPORATING FASTING INTO A SLEEP ROUTINE
Every person’s body responds differently to different situations because of their own unique metabolism and health conditions. The health risks and benefits of fasting should be discussed with your healthcare provider to be sure it is safe for you. Also, ask your healthcare provider what type and length of fasting is most appropriate for your unique situation. While one person may do well with practicing 24-hour fasts a few times a week, many other people will be more successful focusing on a 12- or 16-hour fast by refraining from eating after a specific time, such as 7:00 pm.
Fasting is typically not recommended for people who are:
- Recovering from or experiencing an eating disorder
- Pregnant or breastfeeding
- Trying to conceive
- Experiencing low blood pressure
- Diagnosed with type 1 diabetes or hypoglycemia (low blood sugar)
If you suffer from Gastroesophageal Reflux Disease (GERD), only you and your healthcare provider can decide if fasting is right for you. However, it is likely you will at least be encouraged by your healthcare provider to stop eating a specific amount of hours before bedtime to help reduce the amount of reflux you may be experiencing.
SETTING UP A SLEEP-FOCUSED FASTING ROUTINE
- Timing is everything. The later you stay up, the more likely you are to eat more and break your fasting routine. Stick with a bedtime that is before midnight to maximize your success.
- Stay hydrated. We often end up seeking food when we are actually just thirsty. Try a cup of decaffeinated tea or a glass of water rather than food if you feel hungry at night. Even minor dehydration can result in restless sleep and increase your likelihood of snoring due to a dry nose, mouth, and throat. Just be careful not to drink so much that you need to use the bathroom several times during the night as this will disrupt your sleep.
- Pay attention to food quality. If you are eating fewer hours or even skipping eating entirely on some days, what you eat becomes even more important for overall health and sleep. Therefore, maintaining a proper balance of proteins, fats, and fiber-rich carbohydrates is key to keeping blood sugar levels under control. This means your doctor may recommend you choose whole foods including healthy oils, nuts, lean proteins, lots of fruits and vegetables, and avoid sugar or processed foods. This will provide your body with the energy and nutrients it needs and will also help you sleep better.
You should always speak to your healthcare provider before making changes to your health behaviors. If your healthcare provider says fasting is something you can consider, you can determine together which fasting pattern is safest for you—and which method you are most likely to be successful at following. The great news is that fasting is likely to improve your other sleep health too due to fewer issues with snoring and reflux. Also, fasting improves heart health conditions and reduces the risk for several other diseases.
You can learn more about how sleep impacts your health for years to come from our previous post, entitled Protecting Your Future Health One Night’s Sleep at a Time. And, of course, sleep experts at Brooklyn Bedding are always available to help support you in prioritizing your sleep.
Whether you are concerned about brain health, energy levels, reflux, snoring, blood sugar control, or body weight and metabolism, each is influenced by many different health behaviors—most of which point back to your sleep health.