• Late-night eating can make it harder to fall (and stay) asleep because it interrupts your natural circadian rhythm. This happens because food requires digestion, which affects hormones and metabolic activation.
  • While a bedtime snack may sound tempting, if you want to sleep soundly, it’s better to skip it.
  • In your Oura App, you can tag “Late meal” to see how late-night eating impacts your own personal sleep quality.

Midnight snack? Not so fast. Late-night meals can hurt your sleep. Research has linked late-night snacking to increased sleep latency (aka it’ll take you longer to fall asleep), sleep efficiency, and the amount of REM and deep sleep you’re getting.

Late-Night Eating: Good or Bad For Your Sleep?

Throughout the night, you move through different stages of sleep: rapid eye movement (REM) sleep and non-REM sleep, which is further divided into different phases, including deep sleep. Research has shown that late-night eating can disrupt the natural progression of sleep stages, causing you to wake up feeling tired and lethargic.

Oura members can use the Tags feature to log when they have a late-night meal to analyze how it affects their Sleep Scores over time. Many members report that eating late causes a drop in sleep quality, resulting in a lower Sleep and Readiness Score. 

When you eat, our digestive systems kick into gear, ready to break down and process the nutrients. This process requires energy and metabolic activity – so if you eat late a night, it keeps your digestive system “awake” and engaged, long after you hit the pillow.

The digestive system, hard at work, releases digestive enzymes and increases blood flow to the gastrointestinal tract to facilitate nutrient absorption. These physiological responses can elevate your body temperature and metabolic rate, creating a state of increased alertness and activation that can interfere with the natural progression into sleep. If you consume heavy or high-fat meals late at night, it can prolong the digestion process, further delaying your body’s transition into a more restful state. 

This is reflected in the research: A 2020 study found that when participants ate within three hours of bedtime, they woke up more during the night, experiencing more disrupted, low-quality sleep. And this was after adjusting for confounding factors, like body mass index, isolating the evening snack as the culprit!

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Late-Night Eating and Your Circadian Rhythm

As with many health topics, this is another topic that fits the “all things in moderation” mantra. In sum: An occasional late-night meal isn’t going to harm your health. But if you notice it becoming a habit, it can disrupt your circadian rhythm.

The circadian rhythm is your body’s internal clock. It’s influenced by external cues, like light exposure and meal timing. Eating late at night, when your body expects to be in a fasted state, can affect hormone release. Specifically, late eating can delay the onset of melatonin secretion, preventing you from feeling tired.

Oura member Nicole V. discovered how late-night eating affected her sleep once she started using Oura. “I noticed the effects of eating late on my heart rate (elevated) and overall Readiness Score — my poor relationship with food was making my body work overtime,” she tells us. “Seeing the effects of my poor habits validated in real data has given me the motivation to find more balance in my life. ”

What you eat before bed also matters. Eating a carbohydrate-rich meal can cause a blood sugar crash in the middle of the night after a late-night meal causing cortisol levels to rise, and frequent wake-ups. Heavy, high-calorie meals can cause greater sleep latency, and meals high in sodium can increase restlessness, and worsen sleep apnea.

Tips For Better Sleep

  • Avoid big meals close to bedtime: Big meals elevate your metabolism and resting heart rate before bed and ultimately harm your sleep. It’s best to avoid heavy, carb-loaded meals three hours before bedtime to give your body time to digest.
  • Cut caffeine after midday: Be aware that the effects of a late afternoon cup of coffee can last much longer than you’d think. Caffeine can cause restless sleep and make it harder to fall asleep. Keep in mind that soda, tea, and even chocolate can contain enough caffeine to have an effect. 
  • Refrain from using wine as a sleep aid: While alcohol may help you relax before bed, too much can rob you of highly valuable REM sleep. Once the alcohol’s effects wear off, you’re more likely to wake up throughout the night and have lighter sleep overall. 
  • Opt for healthier late-night snacks: When hunger hits, you don’t have to ignore your body’s signals. Opt for a healthier evening snack that has balanced macronutrients, like one these delicious bedtime snack ideas.
  • Stay hydrated – but watch your water intake! Dehydration can impair sleep quality. But chugging water just before bed can too! Avoid drinking water within 30 minutes of your bedtime; if you are thirsty, take small sips. This can prevent you from waking up during the night to use the bathroom.
  • Allow two to three hours for digestion: Your digestive system is generally more efficient during the day. Aim to eat dinner two to three hours before bed, to allow time for your body to begin digesting your meal. 

READ MORE: 8 Foods and Drinks For Better Sleep (And The 4 To Avoid!)