The direct connection between what you eat and how well you sleep

What we eat during the day has a big impact on our sleep. Here are tips on eating right that will help you improve the quality of your sleep

Man taking food from fridge

Nutrition plays an important role in sleep, but probably not in the way that you’d think. That’s because one of the most significant influences on sleep is adequate calories. What I have found in my informal, unscientific study is that most people I speak with who have sleep problems are not eating enough. This can manifest as a variety of sleep disturbances, including difficulty getting to sleep, difficulty staying asleep and early morning waking often accompanied by anxiety.

Why you shouldn’t eat less

There are some scientific reasons why under-eating can produce sleep disturbances. For one thing, limited human studies show that short-term fasting reduces melatonin production. Whether or not the same effect is seen in chronic calorie restriction is unclear, but it is plausible. And for another thing, even mild chronic calorie restriction can alter hormone levels and patterns, including thyroid hormones, cortisol and adrenaline. One common pattern among those who under-eat is for stress hormones to peak early in the morning causing waking and anxiety or stressful feelings.

Often, sleep disturbances attributed to under-eating can be temporarily alleviated by eating, especially something with easily digested sugar and perhaps a bit of salt in order to suppress stress hormone production. Therefore, I find that eating a bit of honey is often enough to help people get to sleep or return to sleep.

I find that eating a bit of honey is often enough to help people get to sleep or return to sleep

However, in the long run, increasing caloric intake and especially making sure that one isn’t restricting carbohydrates too greatly, tends to be essential in order to improve sleep duration and quality. For most people, that means eating a minimum of 2500 calories a day, though sometimes requirements may be higher [men, young people, pregnant or breastfeeding women, sick people and active people in particular may have significantly higher caloric requirements]. In some cases it is necessary to eat significantly more calories during a recovery phase, sometimes upward of 4000 calories a day for many months, in order to restore balance. So what I have found, again, in my unscientific study, is that people I communicate with tend to sleep better when they eat more rather than less, and many people are surprised to find that they have been eating too few calories.

Increase your carbohydrate intake

Under-eating is a major cause of sleep problems from what I’ve seen, but it certainly isn’t the only nutritional factor in sleep problems. Carbohydrate restriction is another major contributor; carbohydrates help to get some nutrients into the brain to produce the hormones necessary for sleep; they also provide glucose, which is one of the two primary fuel sources of the body, and by most accounts, the preferred fuel source. Certainly, the brain requires glucose and if you fail to eat enough carbohydrates your body will produce glucose from other things to keep your brain alive.

People tend to sleep better when they eat more rather than less, and many people are surprised to find that they have been eating too few calories

The brain is fuelled using glucose that comes from stored energy in the liver. That stored form of glucose is called glycogen, and the liver can only store about 100 grams give or take, which means that if the liver is not well supplied, it is possible that sleep can be interrupted because of the stress of running out of the main reserve of brain fuel. People often find that eating substantial amounts of carbohydrates in the evening benefits their sleep.

There are other factors that are shown to influence melatonin levels, though it isn’t always clear that the effects will be substantial enough to influence sleep. For example, one study showed that eating orange, pineapple or banana significantly increased blood levels of melatonin, but was probably not enough to influence sleep. [Melatonin is present in the blood during daylight hours in small amounts, serving as an antioxidant and performing other functions, but the levels are much lower than at night.]

What to consume for better sleep

Vitamin B6 and folic acid

Vitamin B6 and folic acid are necessary for the formation of serotonin and so might be helpful for sleep when supplied in adequate amounts in your diet. This is sensible, and so adequate amounts are a very good idea, but there doesn’t seem to be any evidence that more is better. So if you eat a varied diet that includes meat [especially some organ meat], dairy, fish, potatoes, bananas, oranges and some green vegetables, you’re most likely covered when it comes to B6 and folic acid. Studies show little benefit from taking supplements, though. Of course that doesn’t mean that some people might not benefit. But most won’t. If you supplement with either of these vitamins, do not take more than the recommended daily allowance and use the active forms, which are less potentially toxic. Still, be cautious when taking supplements, particularly B6, since excess can lead to neuropathic symptoms.

Magnesium and zinc

It has been theorised that magnesium and zinc may also help convert serotonin to melatonin. However, studies don’t show any benefits from taking supplements of these as long as people have adequate dietary levels. If you eat some meat, especially red meat, and/or seafood, you’re likely getting enough zinc. Magnesium, on the other hand, may be more challenging to acquire through food, and, reportedly, many people are deficient. If you eat fish, dairy and green vegetables, you may get enough magnesium in your diet. If you choose to supplement, then you can opt for oral or transdermal supplementation.

  • Oral magnesium supplements are often poorly absorbed, leading to gastrointestinal discomfort and loose stools; so look for the well absorbed forms such as magnesium citrate, malate, or glycinate and start with small amounts, increasing slowly to avoid gastrointestinal problems.
  • For transdermal supplementation, one of the most relaxing and least expensive options is to soak in a warm Epsom salt bath. Soaking in an Epsom salt bath before bed can be very relaxing for many people and often improves sleep quality.

Omega-3 fatty acid

Although there aren’t any studies that show that an omega-3 to omega-6 fatty acid ratio affects human sleep, there is reason to suspect that it might. When omega-6 fatty acid levels are high, inflammation can be high. Therefore, reducing omega-6 fats in the diet [corn oil, soy oil, canola oil, and other vegetable oils excluding olive, coconut, and palm] and including some omega-3 fatty acid source such as fatty fish [sardines may be the best because they are lowest in mercury of all fish] may help to improve sleep.

Sleep and your wellbeing

Is sleep a solution to all your problems? It is not. But getting sufficient sleep over time can have surprisingly positive effects. And if health problems were caused by insufficient sleep in the first place—whether those are heart problems, blood sugar problems, mood problems, energy problems, or any other sort of problems—then replenishing your sleep stores and maintaining an adequate quantity and quality of sleep can work miracles in some cases. Even if getting enough sleep won’t solve everything, it can provide a necessary foundation for health and wellbeing.


This was first published in the May 2015 issue of Complete Wellbeing.

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