Missing out on sleep is a big deal for what and how we eat!
KEY POINTS
Sleep loss influences brain function and seems to majorly affect how and what we eat
Sleep loss appears to increase our desire to eat more unhealthy, sugary foods
Sleep loss may dramatically increase how many calories we eat
Brain imaging studies show sleep loss has been linked to changes in brain activation and function
Insufficient and low-quality sleep are issues faced by a growing percentage of the population, affecting millions of people in the United States and many more throughout the world. Missing out on quality sleep is more than just an inconvenience. Research increasingly shows that good sleep plays a key role in maintaining healthy brains and bodies. One little-known pathway by which sleep issues may directly influence our health relates to our food choices. Here are some of the major breakthroughs connecting sleep loss with our dietary choices.
Sleep loss may increase our preference for unhealthy foods
In a study from 2020, researchers tested whether there was a link between sleep loss and people’s preference for sugary foods. After either getting good sleep or being sleep deprived, people were told to taste 5 separate samples with varying degrees of sugar added to them. They found that people who got insufficient sleep had a stronger preference for the sugary options. Additionally, the low-sleep group went to select more calories from carbohydrates at breakfast after their sleep loss.
Another study from 2022 published in the journal Sleep looked at the effect of sleep loss on adolescent’s food preferences. They found that among adolescents getting 6.5 hours of sleep opportunity a night (versus 9.5 hours), there was more consumption of added sugars, carbohydrates and less consumption of fruits and vegetables.
Once we’ve eaten unhealthy foods, sleep deficit appears to make it harder for our bodies to process them. Specifically, sleep debt has been linked to more trouble handling the glucose in our meals. That may mean higher levels of blood sugar for longer periods of time, both of which may be dangerous for our overall and brain health.
Sleep loss may increase our overall calorie intake
In a review of studies published in 2018, researchers concluded that sleep restriction led to a significant increase in hunger, calorie consumption and even weight gain. These types of results have been replicated in other studies as well. A 2021 review of 50 separate studies concluded that sleep restriction may increase calorie intake, number of eating occasions and portion size.
One of the biggest reasons why sleep loss may be connected to changes in our appetite and calorie consumption may have to do with specific appetite-related hormones. It’s been consistently shown that specific hormones released by our gut play a big role in our levels of hunger. Perhaps most notably, higher levels of a hormone called ghrelin have been linked to increased hunger and calorie consumption. That’s why it’s notable that sleep issues ranging from short sleep duration to overall sleep deprivation are linked to higher levels of ghrelin.
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What’s actually happening in the sleep deprived brain?
If we’re making different decisions around food as a result of sleep loss, we’d have to expect that there are changes happening in the brain. In fact, some of these changes have been explored through imaging and other techniques. In one study, researchers found that compared to well-rested people, those who were sleep deprived had increased activation in a part of their brain called the anterior cingulate cortex when they looked at pictures of food. This activation directly related to people’s subjective hunger.
Other research has shown that sleep loss is linked to alterations in brain activity in a part of the brain called the prefrontal cortex. This is especially relevant to food decisions, as the prefrontal cortex is tasked with helping us make well thought out decisions, and key to healthy self-control.
It’s also interesting to note that good sleep promotes clearance of waste buildup in the brain. Recent research has shown that sleep deprivation significantly impairs this process. It’s thought that the waste removal process may influence levels of inflammation in the brain, which is notable because higher inflammation has been linked to more impulsive decision-making. Impaired waste clearance in the brain as a result of poor sleep has already been linked to longer-term implications for brain health, but as the research expands, we may see that it has additional relevance to our decision-making and day-to-day brain function.
Putting it together:
Sleep loss comes with a wide range of consequences from worse focus to worse mood. But it may additionally alter the brain in a way that promotes worse dietary choices. This is all the more reason for us to treat our sleep with reverence, and prioritize it each night. Though our lives can sometimes get in the way of getting consistently good sleep, we can help optimize our nightly shuteye through simple steps including sticking to a consistent sleep schedule, keeping our rooms dark and cool and instituting a wind-down routine before bed that minimizes exposure to artificial light.
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A version of this article I wrote was also published on Psychologytoday.com