A dietitian’s guide on what to eat for a good night’s sleep

If there’s one thing the average adult wants more of, sleep would be close to the top of the list.

For busy adults, it’s not only about getting enough sleep. It’s also about getting restful, good quality sleep, minus the 2am insomnia, night sweats and constant thoughts and worries affecting our ability to not only fall sleep, but to stay there.

While there are plenty of herbal remedies and supplements that claim to aid sleep, there’s also plenty of science on the subject, so if great sleep eludes you, it’s worth checking your diet to see if any changes may help with sleep volume and quality.

The relationship between food and sleep

While many food-related folk remedies are just old wives’ tales, the idea that a glass of warm milk before bed can help you sleep actually has some scientific backing. Protein-rich foods, including milk, turkey, eggs and fish, as well as leafy greens and nuts, contain the amino acid tryptophan.

When metabolised, tryptophan is converted into serotonin and melatonin, both hormones intricately involved in regulating the sleep/wake cycle. As such, consuming foods rich in tryptophan within one to two hours of sleep should aid the process.

A review of research on dietary patterns and sleep reveals that the Mediterranean diet shows the strongest association with an improvement in sleep quality across available self-reported data. While this data is relatively general, it does suggest a positive link between improved sleep and eating greater volumes of fresh food, less processed foods, and a diet with strong anti-inflammatory properties.

Meal timing

A research area less frequently investigated, but one that theoretically makes sense, is the way meal timing affects sleep. Busy, modern life can cause many people to eat their largest meal late in the evening. This can affect digestion, blood sugar, and physical comfort. Indeed, emerging research shows that meal timing, as well as the number of meals, does affect sleep.

A recent study of more than 7000 adults found that eating later in the day and more frequently were both significantly linked to poorer sleep quality. This suggests that one of the simplest ways to improve your sleep is to eat your final meal of the day earlier.

The sleep superfoods

Kiwifruit

It may not be the first food that comes to mind when preparing for deep slumber, but kiwifruit has been shown to support sleep quality and duration in a small study conducted with athletes. Published in the journal Nutrients, 15 elite athletes were asked to eat two kiwifruit one hour before bed over four weeks. While self-reported, there were significant improvements across a range of sleep measures, which were attributed to the natural melatonin content of kiwifruit, as well as its high vitamin C and antioxidant content.

Sour cherry juice

Not commonly found in Australia, sour cherry is increasing in popularity as a dietary supplement due to research that suggests cherry juice appears to help induce sleep. Cherries are naturally high in the amino acid tryptophan, as well as melatonin. Of the research available, adding a glass of cherry juice to your diet before bed appears to help extend sleep duration and aid sleep in those who have difficulty falling asleep.

Magnesium

Magnesium, a micronutrient found naturally in leafy greens, nuts, seeds, and whole grains, has gained recent attention for its benefits to muscle recovery, brain function, and sleep. Research looking at the role of concentrated magnesium L-threonate consumed in supplementary form, published in the journal Sleep Medicine, found that of 80 adults with reported sleep issues, those who supplemented magnesium L-threonate for three weeks reported improved sleep quality, energy, mental alertness and mood with no negative side effects.

And what to avoid

Watch your caffeine

While many of us may be interested in foods that can aid sleep, it’s important to realise that some foods can also hinder it. One silent sleep saboteur you may not have considered is caffeine, which can slip into the diet via a wide range of “healthy” foods, including dark chocolate, cola and energy drinks, and coffee and tea (including green tea). The stimulatory effects of caffeine can be experienced for several hours after consumption, which means that a sneaky hot chocolate or a few squares of your favourite block after dinner may unknowingly be affecting your sleep.

Avoid processed meat

There is also growing evidence to suggest that processed foods, in particular processed meats such as salami, are associated with sleep issues. A small study published in the American Journal of Lifestyle Medicinefound that of 104 patients recently diagnosed with obstructive sleep apnoea, those who were overweight and who ate a diet high in fat had sleep apnoea twice as severe as others. In addition, there was a specific association between processed meat consumption and sleep apnoea severity.

Consider your wine habit

While a glass of wine may seem like a great way to relax after a long day, alcohol is one of the worst substances you can consume for sleep quality. Specifically, it significantly affects the quality of REM sleep. The more alcohol we drink (even with a relatively small amount, or just two standard drinks), the more pronounced the effect. Ultimately, this means that if quality sleep is on your mind, the less alcohol you consume, the better.