When it comes to sleep, there’s a wealth of advice online about what you should or shouldn’t eat and drink at night.
In my experience, the impact that food and drink choices might have on your sleep probably depends on your specific circumstances. For example:
- If you already have a healthy and well-balanced diet, small changes might not make that much difference.
- If you don’t have a good diet and tend to eat a lot of junk food (especially at night) a few key changes might help.
- Even if you have a relatively healthy diet already, it’s good to eat a variety of food, get a good balance of nutrients, and perhaps see if you include food that’s high in sleep-promoting melatonin.
- For most people, there are some food types to avoid before bed.
Let’s take a closer look at what researchers have uncovered about the links between food and sleep.
What does research tell us?
There’s been a lot of research into diet and sleep in recent years – if you search online, there are many studies available to read. But there are a few that have caught my eye in particular.
One of the most comprehensive reviews of the relationship between diet and sleep was carried out by researchers in 2014.
They based their analysis on the outcomes from large sleep surveys. They found that many aspects of your diet can indeed affect your sleep. For example, people who had the least amount of sleep tended to eat the most carbohydrates and drink the least plain water.
In 2018, British researchers looked at the diets of 1612 adults. They found those who slept 7-8 hours on average ate the most fruit and vegetables. Those who slept less than 7 or longer than 8 had the least amount.
In 2013, researchers found that normal sleep times were associated with the most variety of food in the diet.
What should you eat?
Low Glycaemic Index (GI) foods
It’s better to eat food which is low on the Glycaemic index before bed. This is because high GI food will raise the blood sugar faster, when it’s preferable to keep your blood sugar stable.
Some good examples of low GI food are:
- Wholewheat pasta
- Multigrain bread
- Brown rice
- low-sugar wholegrain cereal
Most vegetables are also low GI, and you should include plenty of fruit and vegetables in a low GI diet.
You can have dairy products like milk and cheese, eggs, fish and lean meat. If you’re eating these in the evenings, try to avoid higher fat content; low-fat dairy options are better.
Food containing melatonin
Melatonin is a hormone which plays an important part in sleep through helping to regulate your body clock. It’s produced naturally in the body, and there are also some good food sources which might help boost the level in your body.
In 2017, researchers in China and Hong-kong published a fascinating study of the melatonin content of a vast range of food.
They said in their report:
Melatonin has been reported to improve sleep efficiency and it was found that eating melatonin-rich foods could assist sleep.
Here are some of the foods they found had the highest melatonin content:
- Nuts (pistachio had the highest amount)
- Mushrooms (e.g. Lactarius deliciosus, Boletus edulis, Agaricus bisporus)
- Legumes and seeds (e.g. white and black mustard seeds, soybean seeds, mung bean seeds)
- Kidney beans
- Human and cow milk
- Some corn types
- Pigmented rice (e.g. black rice)
- Tart cherries
- Some medical herbs (e.g. St. John’s Wort and Huang-qin)
Food containing tryptophan
Food containing the amino acid tryptophan are worth adding to the diet. Tryptophan is used by the body to make serotonin which is then used to make melatonin.
Food that contains tryptophan include:
Food containing calcium
Food containing calcium might help you sleep because a lack of calcium can show up as a factor involved in stress and not being able to relax.
Food containing Magnesium
Magnesium has been recommended by many nutritionists as aiding relaxation of both the body and mind. So it’s another mineral to keep in mind when preparing evening meals.
You can find magnesium in:
- Black beans
Get your vitamins
If you eat a balanced diet with plenty of variety, you should naturally be consuming enough of the nutrients we all need to be healthy in general.
B vitamins have a role to play because they are involved in the biological processes involving tryptophan, serotonin and melatonin.
So eating animal proteins, oats, nuts, avocados, bananas, green vegetables and whole grains might be worth considering.
It’s also important to get enough vitamins D and C. Foods that are good for vitamin C include:
- Dark leafy greens
- Citrus fruits
On the other hand, vitamin D doesn’t really come from food and the best source is getting sufficient exposure to daylight and, if possible, sunshine.
It’s important to stay hydrated by drinking enough water during the day. It might not stop you falling asleep, but dehydration can result in lower quality sleep and feeling sleepy the next day.
But interestingly, researchers emphasize the importance of drinking plain water as opposed to other liquids.
What food should you avoid late in the evening?
You probably noticed that everything listed so far is fairly healthy food. There’s no high sugar content food listed and this is the key really.
Try to avoid food which is processed – think brown rice, pasta or brown bread instead of white bread. Stay away from sweet treats and snacks.
Very spicy food is also good to avoid late in the evening.
The closer it gets to bedtime, the lighter your evening meal should be. If you live in a country where the main meal of the day is lunch, or in the afternoon, then you’re doing the right thing where sleep is concerned.
For those people used to dinner being the big meal, try to keep it a minimum of 2-3 hours before bedtime – more if possible. If you have to eat late, keep it light.
High-fat diets bad for sleep
Virtually any health publication will tell you that a high-fat diet is bad for you. The usual reasons quoted are related to weight gain or bad cholesterol and the consequent increased risk of health problems, such as diabetes and heart disease.
In 2016, researchers at the University of Adelaide studied the eating habits and sleep of 1,815 men in Australia over a one year period.
They found that those with a high-fat diet suffered from two common problems:
- More daytime sleepiness.
- A significantly higher probability of having sleep apnea.
They also found that these increased risks weren’t directly associated with having a higher body-mass index. This suggests that the high fat intake itself may be the problem, rather than weight gain.
The researchers concluded that the high-fat diet may interfere with your internal body clock, resulting in disruption to sleep.
What are good bedtime snacks?
It’s important to note that nighttime snacking on junk food isn’t advised by sleep experts – no more crisps, chocolate or sweets while watching a late-night movie!
Researchers in 2018 found that nighttime snacking was associated with unhealthy cravings, diabetes, and obesity.
One of the researchers, Michael A. Grander, was reported by Science Direct as saying:
Laboratory studies suggest that sleep deprivation can lead to junk food cravings at night, which leads to increased unhealthy snacking at night, which then leads to weight gain.
So if you do feel peckish at night, try to avoid junk food or eating too much. Some examples of more appropriate bedtime snacks might include:
- Low sugar cereal
- Cottage cheese on toast
But really, it’s better to eat at a stable and sensible rate throughout the day. If you eat too much before bed, not only can it keep you awake but it’s associated with negative health outcomes. But going to bed hungry isn’t ideal either, so try to eat well at sensible times during the day.
It’s not known if there’s a miracle wonder food that’s guaranteed to improve your sleep. But if you stick to a normal healthy and balanced diet, you may find it makes a difference.
I suggest that you try not to eat heavy, sugary, spicy or very fatty food before going to bed. If you do feel like a light snack before going to sleep, keep it healthy.
You could try picking something from the food discussed in this article and use your imagination to come up with a good light snack.
For many people, it might be a matter of trial and error. You could try keeping a sleep log or use a sleep tracker to see what works for you.
What do you snack on in the evening? Have you found some food helps you sleep, while other food keeps you up? Let me know in the comments!