It’s hard to imagine that we spend one-third of our life sleeping and that it’s as essential to our life as eating, drinking and breathing are. It’s often one of the lifestyle recommendations we are asked to consider. Mainly because most of us for one reason or another, are not getting enough of it! Indeed a lack of sleep can lead to health problems.
We need sleep for the brain and body to rest, recharge and do much-needed repair. Chronic lack of sleep can increase the risk of high blood pressure, cardiovascular disease, diabetes and depression (1). Research also shows that reduced sleep impacts our food intake, which may explain why many of us crave more caffeine and fatty, sweet, and salty foods!
“The way you feel while you are awake depends in part on what happens while you are sleeping” (2)
How can sleep influence our diet?
Our sleep and diet have a complex, although important, relationship. Getting sufficient sleep is associated with healthier body composition, while conversely, diet can influence the quality and quality of our sleep. Awareness of the connection allows us to optimize both in order to eat smarter, sleep better, and live a healthier life.
- Research shows that reduced sleep impacts the amount of food that we intake, but it can also influence the types of foods we reach for. Likewise it can effect the portion sizes we consume and result in increased food cravings (3). This means that we eat differently when we are tired and this can be an added challenge especially when we are trying to eat better.
- Changes in appetite and hunger hormones (leptin and ghrelin) can lead to poorer nutritional choices with sleep deprivation (4). These foods are often high-calorie nutrient poor carbohydrate or fat-rich foods. Late-night snacking can then increase, as we try to sustain energy and relieve tiredness.
- A good night’s sleep has been shown to improve dietary decision-making and energy. This facilitates more physical activity further supporting our physical and mental health.
Changes in the gut microbiome population have also been observed with reduced sleep. These changes have been associated with changes in insulin sensitivity as well as changes in metabolism. However, more research is needed here (5).
How much sleep should we be getting?
So how much sleep should we be getting to optimise our health? The National Sleep Foundation have made the following recommendations of hours/day (6):
- School-aged children: 9-11
- Teenagers: 8-10
- Young adults and Adults: 7-9
- Older adults: 7-8
However, it’s important to remember that sleep differs by individual. Our individual needs can be determined by factors like physical activity level and overall health. So, sleeping an hour more or less than the guidelines may be acceptable depending on your circumstances.
Can our diet help us sleep better?
Developing good sleep hygiene (consistent bed routine, dark cool room and disconnecting from electronic devices) is one of the best things we can do to ensure more quantity sleep. There are considerations too in what we eat, that can support better sleep. Some of these include:
- Ensuring you have a balanced healthy diet, with lots of research showing that the Mediterranean diet improves sleep quality as well as heart health (7).
- Certain foods can hamper sleep, like too much caffeine and alcohol. These can contain stimulants like caffeine, the effects of which can take as long as 8 hours to wear off fully, therefore hindering our sleep.
- Large meals late at night can also delay sleep due to indigestion. Opting for a light snack (protein and a carbohydrate) can be a better alternative that maintains blood sugars level until the morning.
- Tryptophan (a precursor to the sleep-inducing hormones serotonin and melatonin) food sources like eggs, poultry, meat, fish and cheese can have a sedative effect. Note these are best consumed with a carbohydrate food.
It’s also important to remember that sleep problems can also be due to sleep disorders. If you feel that this could be the case, its important to consult with your GP to understand what options are available.
For the rest of us, it’s as simple as getting as much quality sleep as possible, to allow that much-needed rest and repair. So that we have the best chance of making the best food choices the next day to sustain our health.
- Brain basics: Understanding sleep, National Institute of Neurological Disorders and Stroke. U.S. Department of Health and Human Services.
- Why is sleep important? (2022) National Heart Lung and Blood Institute. U.S. Department of Health and Human Services.
- Yang, C.-L., Schnepp, J. and Tucker, R. (2019) “Increased hunger, food cravings, food reward, and portion size selection after sleep curtailment in women without obesity,” Nutrients, 11(3).
- Spiegel, K. et al. (2004) “Brief communication: Sleep curtailment in healthy young men is associated with decreased leptin levels, elevated ghrelin levels, and increased hunger and appetite,” Annals of Internal Medicine, 141(11).
- Parkar, S., Kalsbeek, A. and Cheeseman, J. (2019) “Potential role for the gut microbiota in modulating host circadian rhythms and Metabolic Health,” Microorganisms, 7(2).
- Hirshkowitz, M. et al. (2015) “National Sleep Foundation’s updated Sleep duration recommendations: Final report,” Sleep Health, 1(4).
- Muscogiuri, G. et al. (2020) “Sleep quality in obesity: Does adherence to the Mediterranean diet matter?,” Nutrients, 12(5).