Sleep is widely recognized as playing a vital role in our overall health and wellness—alongside diet, stress management, and exercise.
Recently, researchers have been learning more about how poor sleep influences our dietary choices, as well as how diet influences sleep quality. Not sleeping for long enough or poor quality sleep are both associated with increased food intake, a less healthy diet, and weight gain. Lack of sleep can lead to increased snacking and overeating, especially calorie-rich foods high in fat and carbohydrates thanks to the chemical rewards the brain delivers when we eat these unhealthy foods.
Essentially, poor sleep drives your body to find high energy foods to keep you awake which makes fighting the cravings for unhealthy foods difficult to resist. On the other hand, when we sleep well, our appetite hormones are at a normal level and we don’t crave unhealthy foods as much.
The Science of Sleep
All cultures around the world have traditions about which foods promote sleep. Foods such as milk, chamomile, kiwi, and tart cherries have all been said to help us get a good night’s sleep. Given the way food affects us on a day-to-day basis, it is not surprising that our diet affects our quality of sleep. What we eat also has a big impact on our organ function, immune system, hormone production, and brain function.An important hormone that controls our sleep patterns is melatonin. Melatonin is produced in the brain and the amount of melatonin you produce and how efficiently our brain uses it is affected by our diet. One of the biggest influences on our melatonin levels appears to be our intake of a type of protein called tryptophan. Tryptophan is an essential amino acid—the building blocks of proteins. Essential amino acids are a group which our bodies cannot make and can only be sourced through diet.
Other nutrients that appear to be helpful for sleep include B vitamins and magnesium. This is because they help tryptophan to be more available in the body. If your diet is lacking tryptophan, B vitamins or magnesium, it is very likely that your melatonin production and secretion will be affected and your sleep quality will be poorer.
Eat to Sleep
It stands to reason that following overly restrictive diets, or diets that put you at risk of nutrient deficiencies, can affect your sleep. Increasing your intakes of foods rich in specific nutrients, on the other hand, may help to promote better sleep quality and duration.Dairy foods, for example, can be great at helping you sleep. Not only is dairy an excellent source of tryptophan, but it also contains magnesium and B vitamins which help to promote the activity and availability of tryptophan. Nuts, like dairy, also contain all the nutrients known to promote melatonin production and support its release.
Fish is another great source of tryptophan and B vitamins. Fish with bones, such as sardines, will also provide magnesium. Including fish in your diet regularly may help to promote healthy melatonin production when you need it. Pulses, beans, and lentils also contain high amounts of tryptophan and B vitamins. Adding some tofu or paneer to a vegetable stew or curry can also help to increase your likelihood of having a great night’s sleep. You could also add in some soy—which is another good source of tryptophan.
And if you’re still struggling to sleep, it might be that you’d benefit from some meat. Meat of all kinds contains all the essential ingredients for a good night’s sleep. So if you can’t nod off at night, maybe think about adding some lean meat to your diet.
If you find yourself hungry before bed, for the ideal bedtime snack, try a glass of semi-skimmed or skimmed milk, a small banana or a few nuts—all of which can really help to improve your sleep and your willpower the next day. It’s also worth pointing out that it takes around an hour for the tryptophan in foods to reach the brain, so don’t wait until just before bedtime to have your snack. And it’s also advisable to have a balanced diet that includes plenty of foods that are high in tryptophan throughout the day to optimize your chances of a good night’s sleep.
Sophie Medlin is lecturer in nutrition and dietetics at King’s College London. This article was first published on The Conversation.