Carbohydrates, along with fat and protein, are macronutrients that the body needs in large amounts. Carbs are essential components of a healthy diet, providing the body with energy and assisting in the regulation of blood sugar, insulin, cholesterol, and triglycerides.
When to eat carbs, and how many carbs to consume, can depend on your goals. For example, people with diabetes may count carbs and spread them throughout the day to help manage their blood sugar levels. For some, the decision about when to eat carbs is based on how these macronutrients might affect their sleep.
We discuss how eating carbohydrates affects sleep and what type of carbs may be the best choices for an evening snack.
Eating Carbs Before Bed May Help You Fall Asleep
Carbs have a role in regulating the hormones that help you sleep. In some instances, eating carbs in the evening may help you fall asleep. But keep in mind that the relationship between diet and sleep is complex, and it’s difficult for researchers to isolate the sleep-related effects of a specific nutrient.
Studies that have investigated this relationship suggest that people who eat diets high in carbohydrates fall asleep more quickly than people whose diets consist mostly of protein or fat. These studies found that eating carbs a few hours before going to bed, rather than at bedtime, may be the most effective for dozing off quickly.
While carbs may help you fall asleep faster, they could negatively affect how well you sleep. A diet high in carbohydrates may lower your sleep quality, especially if you are eating simple carbs like sugar or refined grains. For instance, high consumption of added sugars in foods has been linked to increased rates of insomnia.
Research also suggests that the amount of carbs in your diet could affect how your body moves through the stages of sleep. High-carb diets may lead to more REM sleep and less deep sleep. Deep sleep is important because it’s when your body and brain are most relaxed, enabling you to wake up feeling refreshed.
What Happens to Your Body When You Eat Carbs?
Carbs are sugars and starches that your body easily converts to sugar molecules, as well as fiber which isn’t broken down by the body. Carbohydrates cause your glucose (blood sugar) level to rise. Refined carbs that cause your blood sugar to rise quickly may bring on feelings of sleepiness.
Eating carbs also affects your body chemistry, boosting brain chemicals that help you get to sleep. Carbs help you feel sleepy by increasing a protein called tryptophan in your brain.
Tryptophan is a building block for both serotonin and melatonin. Serotonin is a brain chemical that controls sleep, mood, and appetite, while melatonin is a hormone that promotes a regular sleep-wake cycle. High levels of tryptophan after eating carbs can increase these chemicals in the brain and make you feel sleepy.
Is It Better to Eat Complex or Simple Carbs Before Bed?
Generally, it’s better to eat complex carbs before bed. Not all carbs are the same. Research suggests that the type of carbohydrates you consume may determine how those carbs impact your sleep.
- Simple carbohydrates: Sugars, including the sugars found in candy and other sugar-sweetened products, are classified as simple carbohydrates. The naturally occurring sugars in milk and fruit are also simple carbs. Your blood sugar rises quickly after you consume simple carbs.
- Complex carbohydrates: Vegetables, whole grains, and beans are sources of complex carbohydrates. Complex carbohydrates take longer for the digestive system to break down, which helps keep blood sugar levels stable. Fiber is also a type of complex carb.
Consuming a lot of simple carbs may negatively impact your sleep quality. Diets high in simple carbs have been linked to shorter sleep, more time spent awake in bed, and less time in restorative sleep stages.
Complex carbs, on the other hand, may boost the body’s melatonin levels. People who eat more complex carbs may also be less likely to experience insomnia. Consuming more of the complex carbs in vegetables has been linked to less tossing and turning in bed and better sleep quality.
What Are the Best Carbs to Eat Before Bed?
A number of foods are both rich in nutrients that promote good health and high in carbohydrates that may help promote sleep.
- Grains: A diet high in whole grains like brown rice, whole-wheat bread, and oatmeal has been linked to a reduced risk of insomnia. Refined grains like white rice, corn grits, and white bread raise blood sugar quickly and may help people fall asleep faster. However, refined grains contain less fiber and natural vitamins than whole grains.
- Fruits: Fruits contain naturally occurring sugars that are excellent sources of carbohydrates. Eating lots of fruit has been linked to better sleep quality. Some research has found that kiwis and cherries in particular may lead to better sleep.
- Dairy products: Including dairy products like milk and yogurt in a balanced diet may improve sleep. Dairy products contain the simple carbohydrate lactose, a naturally occurring sugar, along with other important nutrients like calcium.
Timing Your Evening Carbs
Having a light snack close to bedtime usually doesn’t interfere with sleep, but eating too much may lead to indigestion and keep you awake. As far as carbs are concerned, research indicates it may be best to eat them around one to four hours prior to sleep, rather than immediately before bedtime.
Are Low-Carb Diets Bad for Sleep?
Low-carbohydrate diets, including the ketogenic diet, have been used for weight loss for decades. Some people report experiencing sleep problems as they adjust to a new diet, including diets that restrict carbs.
However, there is no high-quality research in humans showing that low-carb diets reduce sleep quality. In fact, several studies suggest that low-carb diets may even improve sleep for some people.
Talking To Your Doctor About Your Diet
If you’re concerned about how your eating habits are affecting your sleep, it may be helpful to talk to your doctor. Your doctor can evaluate the cause of your sleep issues and recommend appropriate steps to improve your nightly rest.
Additionally, you may wish to discuss your reasons for wanting to cut out nighttime carbs. Carbohydrates are important sources of fuel for the body, so you may want to be cautious about restrictive diets that ask you to eliminate a certain type of food or macronutrient from your diet.
References
About The Author
Staff Writer, Product Testing Team
Alison is a health writer with ample experience reading and interpreting academic, peer-reviewed research. Based in San Diego, she is published in the journal PLOS Genetics and the Journal of Biological Chemistry and has been a copywriter for SmartBug media. With a master’s degree in biochemistry from the University of California, Davis, she has nearly a decade of academic research experience in life sciences. She enjoys helping people cut through the noise to understand the bigger picture about sleep and health. Alison likes to stay active with rock climbing, hiking, and walking her dog.
- POSITION: Stomach Sleeper
- TEMPERATURE: Neutral Sleeper
- CHRONOTYPE: Bear
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