Sugar and Sleep

sugar and sleep

Little children take a bottle of juice to bed. Teens finish off their day with a glass of soda. Adults indulge in a dish of ice cream before bed or a sweet cocktail at a late-night party. These are common habits…but do they interfere with sleep?

The sleep-wake cycle

To understand how sugar affects sleep, it’s important to know how the body regulates sleep. Our sleep-wake cycle is controlled by various hormones and neurotransmitters, including cortisol, melatonin, and serotonin. Cortisol is a hormone that helps us wake up in the morning and stay alert during the day, while melatonin is a hormone that helps us fall asleep at night. Serotonin is a neurotransmitter that plays a role in regulating mood, appetite, and sleep.

Consuming sugar can disrupt the delicate balance of these hormones and neurotransmitters, which can lead to sleep disturbances. One study found that consuming a high-sugar diet resulted in a decrease in slow-wave sleep, which is the deepest and most restorative stage of sleep. Another study found that a high fructose diet reduced time in REM sleep, the dreaming phase of sleep. A third study reported generally poor sleep quality among women who consumed high levels of sweets.  Incomplete sleep like this can leave us feeling groggy and tired, even after a full night’s rest.


Another way that sugar can impact sleep is by increasing the likelihood of waking up during the night. Consuming sugar can cause a spike in blood sugar levels, which can lead to a subsequent crash in blood sugar levels. This can cause us to wake up feeling hungry, thirsty, or needing to use the bathroom. Additionally, sugar can stimulate the brain and make it difficult to fall asleep, which can lead to insomnia.

Sugar can also impact our overall health in ways that indirectly affect our sleep. Consuming too much sugar can lead to weight gain, which is a risk factor for sleep apnea. Sleep apnea is a condition in which breathing is repeatedly interrupted during sleep, which can cause snoring and daytime fatigue. Additionally, consuming too much sugar can increase our risk of developing type 2 diabetes, which is associated with poor sleep quality.

It’s important to note that not all sugars are created equal. Natural sugars, such as those found in fruits and vegetables, are generally considered to be healthy and may even promote better sleep. However, added sugars, such as those found in processed foods and sugary beverages, can have negative health consequences.


So, what can we do to promote better sleep and reduce the impact of sugar on our sleep? One strategy is to limit our consumption of added sugars. The American Heart Association recommends that women limit their added sugar intake to 6 teaspoons per day, while men should limit their intake to 9 teaspoons per day. This can be challenging, given that added sugars are often hidden in processed foods, but it’s a worthwhile effort.

When you eat sweets can also make a difference. It’s best to have a sweet after a balanced meal, since the fiber and protein of the meal will help avoid blood sugar spikes. A lunchtime dessert gives you more time before bed to burn off the sugar, too, so it will be less disruptive to your sleep. Fruit juice with breakfast, a soda or dessert at lunch, or a light sweet after an early dinner will be better for you than a sugary bedtime snack.


Image courtesy of Adobe