We spend about a third of our lives sleeping, and even though we aren’t conscious to witness it, our sleep serves several important functions. While asleep, our brain consolidates memories, detoxifies, and replenishes energy. 4 Meanwhile, our body regulates its immune response and repairs muscles, organs and cells. 5

Those who have trouble sleeping may soon have additional problems to deal with - sleep disorders are associated with the onset of diseases such as cancer, cardiovascular disease, type 2 diabetes and depression, and increased susceptibility to infectious diseases.

Limit Artificial Light after Sunset

The best thing you can do to optimize your sleep is to regulate your circadian rhythm. Your circadian rhythm refers to the cascade of changes your body goes through within a 24-hour period - an important part of that being sleep and the hormonal and body temperature effects accompanying sleep. Your circadian rhythm takes cues from the light in your environment to determine what time of day it is, but in the modern age, we often disrupt that cue with artificial lighting.

We can regulate our circadian rhythm by reducing exposure to artificial lighting after sundown and ensuring that we are exposed to sunlight and bright lighting during daylight hours. Giving your body a consistent wake and sleep time will also help you anticipate when it is time to be alert or sleepy.

Read a detailed guide to regulating your circadian rhythm here.

Keep a Cool Temperature

Your circadian rhythm also governs the cyclical movements of your body temperature. About two hours before bed, your body begins to cool. To support your body’s effort to keep cool and facilitate deep restorative sleep, the room you are sleeping in should be kept at a cool temperature. 

A study published in the journal Diabetes 2 found that sleeping in cooler temperatures (19°C) vs higher temperatures (24 and 27) modulates brown adipose tissue (brown fat) in a way that offers benefits to your metabolism and insulin sensitivity. Bedroom temperature has slowly increased in the United States over a period of 30 years, from 19°C to 21.5°C. Researchers speculate that this could be a contributing factor to the obesity epidemic. 

For optimal deep sleep, restoration, and support of metabolism and insulin sensitivity, opt to sleep in a cooler environment between 15-18 degrees celsius or 60-65 degrees Fahrenheit. 1

Exercise

Regular physical activity is associated with better quality sleep. However, high-intensity exercise late at night can interfere with melatonin secretion that night and delay melatonin secretion the following evening. These findings suggest that the rest-activity cycle has some degree of power to shift the circadian clock. Light exercise did not have the same adverse effect on melatonin secretion. 3

Eating and Drinking

Chrono-nutrition refers to the field that studies the relationship between circadian rhythm and food. Food habits affect your circadian rhythm in three main ways: how consistent or inconsistent your eating routine is, how often you eat, and the time of day you eat. 6 

Eating before bed can result in noticeable issues such as acid reflux or heartburn. If you eat something sweet or caffeinated, you may also find that you cannot relax and drift off comfortably. You should abstain from eating at least 3 hours before bed for best sleep results.

Alcohol impacts sleep. It is common for some people to have some alcohol in the evening before bed; some even say it helps them sleep. However, alcohol actually harms sleep, affecting biorhythms and shortening the REM cycle. 4 Avoiding alcohol before bed, and finding healthier ways to unwind, like a warm bath or meditation, will help optimize sleep quality.

Get Enough Sleep

Insufficient sleep has been associated with an increased risk of developing obesity. Lack of sleep can also make you feel more hungry, often resulting in a higher caloric intake. 

Insufficient sleep can impact hormonal levels in the body - namely leptin, ghrelin, cortisol and growth hormone. Shorter sleep periods can also have detrimental effects on insulin sensitivity. 4

Takeaways

Ensuring sleep quality is essential for a healthy lifestyle - good sleep helps us to show up as our best selves in the present and also helps to promote longevity and prevent disease in the future. Here are some of the actions you can take to improve your sleep:

1. Manage your light exposure after sunset. Exposure to artificial lighting after sunset can harm your circadian rhythm, making it challenging for your body to achieve deep and restorative sleep. 

2. Keep your sleeping environment cool. Sleeping in cooler temperatures is associated with better quality sleep and positive effects on metabolism and insulin sensitivity.

3. Exercise, and exercise at the right time. Regular exercise is associated with higher-quality sleep. Try not to do high-intensity exercise at night, as it may affect melatonin secretion, making you feel less sleepy.

4. Don’t eat or drink alcohol before sleeping. Eating and drinking alcohol before sleeping will inhibit your ability to get your most restful sleep.

5. Get enough sleep. Sleep is essential for the body's optimal function - prioritize accordingly.

Sources

1. What’s the Best Temperature for Sleep? (2022, March 30). WebMD. https://www.webmd.com/sleep-disorders/features/cant-sleep-adjust-the-temperature

2. Lee P, Smith S, Linderman J, Courville AB, Brychta RJ, Dieckmann W, Werner CD, Chen KY, Celi FS. Temperature-acclimated brown adipose tissue modulates insulin sensitivity in humans. Diabetes. 2014 Nov;63(11):3686-98. doi: 10.2337/db14-0513. Epub 2014 Jun 22. PMID: 24954193; PMCID: PMC4207391.

3. Buxton OM, L'Hermite-Balériaux M, Hirschfeld U, Cauter E. Acute and delayed effects of exercise on human melatonin secretion. J Biol Rhythms. 1997 Dec;12(6):568-74. doi: 10.1177/074873049701200611. PMID: 9406031.

4. Sejbuk, M., Mirończuk-Chodakowska, I., & Witkowska, A. M. (2022). Sleep Quality: A Narrative Review on Nutrition, Stimulants, and Physical Activity as Important Factors. Nutrients, 14(9), 1912. https://doi.org/10.3390/nu14091912

5. What Happens to Your Body When You Sleep? (n.d.). WebMD. https://www.webmd.com/sleep-disorders/ss/slideshow-sleep-body-effects

6. Pot GK. Sleep and dietary habits in the urban environment: the role of chrono-nutrition. Proc Nutr Soc. 2018 Aug;77(3):189-198. doi: 10.1017/S0029665117003974. Epub 2017 Oct 25. PMID: 29065932.