There is much debate as to whether or not eating before bed is bad for you, including numerous studies suggesting it can be healthy in some instances, and unhealthy in others. Below we’ll discuss how eating before sleep impacts your body, and examine the effects it has on WHOOP member data.
The standard assumption people often make is that eating prior to going to sleep will cause you to gain weight, with the reason being that your metabolism slows down when you are sleeping. In turn, this will lead to the calories you’ve consumed being stored as fat.
However, most scientific evidence doesn’t actually support this line of thinking. While there may often be a connection between late-night snacking and putting on weight, the more likely explanation is simply that you’re consuming more calories in total by eating extra food before bedtime.
Learn More: How Sleep Affects Weight Loss
At the most basic level, if your body is working to digest food it’s not able to get to as restful a state as it would otherwise. This can cause you to have trouble falling asleep and also reduce the quality of your sleep.
From performance chef Dan Churchill on the WHOOP Podcast:
“Your body doesn’t switch off when it’s digesting at nighttime. So all of a sudden if you look at your WHOOP and it tells you that you’re waking up, [having bad sleep] latency, all that kind of stuff. … Part of the reason your mind might not switch off [while trying to sleep] is because of that connection between your gut and your brain. Your gut is not switching off because it’s digesting food in a way that’s not efficient and your brain, in response, is trying to work out what’s going on so you don’t fall asleep properly.”
The process of digestion may also divert resources away from other restorative aspects of sleep which help your body recover. Additionally, eating late can throw off your circadian rhythm, the body’s 24-hour internal clock that regulates your sleep/wake cycle (more on this to follow).
With the WHOOP Journal feature, one of the many behaviors our members can track each day is whether or not they ate any food close to bedtime (as well as the specific time they ate). WHOOP then provides them with insights into how this behavior affects their physiological metrics.
Byan Johnson, CEO of Kernel, took this analysis to an unprecedented level. Through countless hours of self experimentation, he determined that any food he ate after 10 am caused his resting heart rate to increase that night. Bryan now fasts for most of the day prior to going to sleep, and eats his dinner at 10 in the morning.
While Bryan’s example is obviously very extreme, we decided to examine the data of our members to see what happens when they log eating before sleep.
The results we uncovered make a solid case that eating late is likely detrimental to your sleep. On average, when our members report eating close to bedtime they get 26 fewer minutes of sleep than they usually do. They also average 3% less REM sleep (the mentally restorative stage of sleep) than normal.
On top of that, next-day recovery dips by an average of 10% following late-night eating.
Our analysis took potential confounding factors into account as well, controlling for other behaviors (like drinking alcohol) that you might also engage in when eating late.
What time do you need to eat dinner in order to avoid the likelihood of it hurting your sleep? WHOOP VP of Performance Science Kristen Holmes recommends having your final meal of the day at least 2-3 hours before you plan to go to bed.
Beyond eating early, it’s also quite beneficial to stick to a regular dinner time as best you can. Your body functions better when it runs on a predictable schedule. Consistent meal times enforce this and help regulate your circadian rhythm, which improves the efficiency of your sleep.
If you find yourself hungry before bed, some foods are a much better choice than others. Dairy products can be sleep promoting, and foods with serotonin also prompt your body to produce the sleep hormone melatonin.
Tart cherry juice is high in melatonin itself and is a popular sleep aid, but that’s not going to do much to curb your appetite. A few simple carbs before bed (pasta, white rice, potatoes) may be a decent option, since they are easier to digest than complex ones. And if you’re feeling ambitious, try mixing up this sleep cocktail.
Foods to avoid before bed include anything high in fat or sugar, which require a lot of hard work for your body to process.