Insomnia is one of the most common health-related problems that people don’t talk about. Who wants to admit that they lie awake for hours trying to drift off to sleep? Then, there are people who fall asleep only to awaken a few hours later. The number of people who experience insomnia or have low sleep quality is substantial, and the incidence goes up with age. Difficulty getting a good night’s sleep is more common in women with about one in four women have difficulty falling asleep on occasion and it’s an ongoing problem in one out of seven women.
What are the downsides to lost sleep? Lack of sleep causes short-term issues such as fatigue, memory issues, mood disturbances, and lack of motivation, but studies also show that people who don’t sleep enough have a higher risk of obesity, type 2 diabetes, and cardiovascular disease. Plus, ongoing sleep problems are correlated with higher mortality from all causes.
It’s not surprising that sleep causes mental and physical health issues! During sleep your brain “reboots.” The information you learned that’s in short-term memory is consolidated into long-term memory. Various hormonal changes also take place that impacts your appetite, metabolism, and immune system. Studies show that people who skimp on sleep are more susceptible to weight gain and upper respiratory infections.
But what if you can’t go to sleep? If sleep eludes you, look at your eating habits. What you eat plays a role in how well you sleep and even the timing matters. Factors like when we eat can make sleep easier or harder. Let’s look at how eating habits can impact your ability to sleep.
When You Eat
Before looking at what to eat and not to eat when you can’t sleep, think about food timing. Nature designed your body to eat at certain times of the day, based on your circadian rhythms. You have an internal biological clock that runs by a 24-hour template. It makes the most sense physiologically when you eat during daylight when you would be most active. It’s during these times you have the highest insulin sensitivity too.
What happens when you eat most of your meals and snacks later in the day? Researchers at Brazil’s Universidade Federal de Sao Paulo monitored the sleep of 52 adults in a sleep lab overnight. The participants also kept a food diary for 3 days in a row, including the foods they eat, quantity, and timing. What they found was that eating at night led to significant disruptions in sleep, and these disruptions were more pronounced in women. In particular, women who consumed more calories and fat in the evening required more time to fall asleep and woke up more during the night. They also had delays in entering a phase of sleep called REM (rapid eye movement sleep).
How can you use this information to improve your own sleep quality? Eat your last meal at least 2-3 hours before bedtime. Front load your calories so you’re getting the bulk of your food at breakfast and lunch. As the saying goes, “Eat like a king in the morning and like a pauper at night.”
What You Eat
Then there’s what to eat and not eat to improve sleep quality. Common sense tells us not to drink a venti coffee drink from Starbucks in the evening, especially blonde roast, since it’s higher in caffeine. In fact, lay off of caffeine after 12:00 p.m. if you have a history of insomnia. People metabolize caffeine at varying rates. Caffeine has a half-life of around 5 hours. So, half of it leaves your system after 5 hours and another half with disappear over the subsequent 5 hours. Therefore, caffeine can stay in your system for a while, especially if you’re a slow metabolizer.
You can always switch over to decaf if you enjoy an afternoon cup of coffee. The amount of caffeine in decaf coffee usually isn’t enough to interfere with sleep. Remember, tea, energy drinks, soft drinks, and some medications are also sources of caffeine.
Avoid junk food later in the day. The high sugar content can cause blood sugar extremes that keep you awake or cause you to wake up during the night. In fact, a study of females in Japan found that drinking sugar-sweetened beverages, energy drinks, eating meals at irregular times, and skipping breakfast worsened sleep quality.
Does What You Drink Matter?
What you drink can impact sleep. As mentioned, avoid caffeinated beverages and alcohol. Alcohol may make you sleep at first, but, overall, it worsens sleep quality. In fact, an alcoholic drink in the evening can trigger nighttime and early morning awakenings.
However, there are some beverages that may help you drift off to sleep. One is chamomile tea, an herbal tisane. Chamomile contains a flavonoid called apigenin. After a cup of hot tea, the apigenin in chamomile binds to the same receptors in the brain that the anti-anxiety & sleep class of medications called benzodiazepines do. Therefore, chamomile has a modest anti-anxiety and sleep-inducing effect. A warm cup of chamomile tea before bed may be just what your body needs to unwind.
Another beverage that may help is tart cherry juice. Research shows that drinking one glass of cherry juice in the morning and one in the evening can modestly improve sleep quality. In one study, participants who did this slept about an hour longer. How does it work? Tart cherry juice contains the sleep-inducing hormone melatonin. Plus, components in tart cherry juice block the action of an enzyme that breaks down tryptophan. When more tryptophan stays in your brain, it increases brain serotonin for better sleep.
The Bottom Line
Now you have a better idea of how what you eat and when you eat can impact sleep quality. Avoid junk food, skip the caffeine and replace it with tart cherry juice or chamomile tea. However, eating healthier carbs prior to bedtime combined with protein may help you get more tryptophan into your brain for better sleep. Shift your last meal to earlier in the day too. If you have persistent problems with insomnia, see your physician. Health problems like sleep apnea and health conditions, like an overactive thyroid gland, can make it harder to fall or stay asleep.
- J Occup Health. 2014;56(5):359–68.
- gov. “Insomnia”
- Medical News Today. “How diet may lead to insomnia”
- BMC Psychiatry 18, 153 (2018). https://doi.org/10.1186/s12888-018-1734-7.