How to eat your way to a better night's sleep

New research shows that what we eat can have a significant effect on the quality of our sleep. Photo / 123RF

Instead of buying weighted blankets or tracking your slumber, rethinking the supermarket shop could be the key to a better kip.

We've finessed our bedtime routines, absorbed the science of circadian rhythms, cleared out the bedroom clutter, battened down the blinds and left our phones at the door to ensure our sleep hygiene is spick and span. And yet, a good night's rest remains for many of us as elusive as ever.

We will do anything for some decent shuteye; the global sleep market is now worth £62 billion ($124 billion).

But what if instead of buying weighted blankets and sleep trackers, rethinking the supermarket shop could be the key to buying your way to a better kip?

New research shows that what we eat can have a significant effect on the quality of our sleep.

A study recently published in the journal Annual Review of Nutrition based on research by Columbia University in New York, found that eating a diet containing plenty of fruit and veg, plus legumes and dark whole-grain breads, is associated with better quality sleep.

Rob Hobson, nutritionist and author of The Art of Sleeping, is not surprised by the study's findings: "People who eat more fruit and vegetables generally have a healthier life overall.

"They're probably eating less sugar and drinking less alcohol. What's more, many plant-based foods contain nutrients shown to help with sleep such as magnesium, tryptophan and B6."

Here, he guides us through which foods harm and which help your sleep – and why.

Foods that harm your sleep

There may be some truth in the old wives' tale cautioning against eating cheese before bedtime. Photo / 123RF

White sugar/ fizzy drinks/desserts

Food and nutrition surveys have shown that adults eat twice the recommended maximum amount of six teaspoons of sugar per day. White sugar is referred to as a "free" sugar, which is found in all sweeteners (including honey, agave and fruit syrups). Eating lots of sugar during the day can impact on your quality of sleep during the night and pull you out of a deep sleep.

One study showed that high sugar consumption led to less deep sleep and more wakefulness.

Sugar might also inhibit sleep as it causes the release of a hormone called norepinephrine that can stimulate the brain.

Red meat

If you have a meat-heavy diet, you're eating more calories than you need and therefore you could be putting on more weight, which will disrupt your sleep. Heavy foods aren't good if you suffer from indigestion and reflux; that's going to affect your sleep as well. A better approach would be a piece of lean meat, like fillet steak, with salad and maybe a little rice.

Everyone should watch their red meat intake. Going for poultry (chicken or turkey) would make your evening meal slightly healthier.

Cheese and yogurt (high fats)

If you suffer from indigestion or reflux then high-fat foods can aggravate these problems and keep you awake. They are also foods that can cause you to put on weight and, if you're overweight, you are more likely to snore or suffer from sleep apnea.

Tyramine is an amino acid found in cheese. There may be some truth in the old wives' tale cautioning against eating cheese before bedtime; cheese – as well as bacon, ham, aubergine and red wine – contains a substance called tyramine, which has been linked to migraines.

Foods that help you sleep

Avocado is a good source of magnesium. Photo / 123RF

The Mediterranean diet

The health benefits have been widely researched, and a Mediterranean diet has been shown to help in all areas of health.

Essentially, it involves a high intake of fruits, vegetables, legumes and cereals, a moderate intake of fish, a low to moderate intake of dairy foods and a low intake of beef and poultry.

It also means a high ratio of monounsaturated fats to saturated flats; they can be found in olive oil, avocados, nuts and seeds.

Vital carbohydrates

Tryptophan has a lot of competition to make it across the blood-brain barrier, but including in your diet foods rich in carbohydrates, such as pasta, potatoes and rice, can increase its uptake. These foods elevate the hormone insulin, which helps the uptake of tryptophan in several ways.

A combination of tryptophan-rich foods teamed with carbohydrates may provide the perfect evening meal. Example dinners include turkey stir-fry with white rice, salmon with white pasta and pesto, and veggie chilli with rice or quinoa.

Ironically, white carbohydrates are better than wholegrain ones in supporting tryptophan transfer because they're broken down more quickly, and the release of insulin is more rapid.

Calcium

This is a mineral required to convert tryptophan to melatonin, the hormone that makes you feel drowsy, and research published in the journal European Neurology has found that disturbances in sleep, especially during REM, may be related to low levels of calcium. Be sure to include a good supply of calcium in your diet, with milk, yogurt, cheese, tofu, dark green leafy vegetables, beans and pulses, squash and canned fish.

Magnesium

Magnesium activates the parasympathetic nervous system, which is responsible for relaxation by binding to gamma-aminobutyric (GABA) receptors responsible for quieting nerve activity. By doing so, it may help prepare your body for sleep. Magnesium also regulates melatonin, which guides sleep-wake cycles in the body. Magnesium is found in dark green leafy vegetables, seeds, beans, lentils and pulses, oily fish, wholegrains, nuts and avocado.

Vitamin B6

This vitamin is involved in the production of melatonin, the hormone that controls the sleep-wake cycle. Most of us get enough vitamin B6 as it's available in many foods, but it's also easily depleted as a result of stress or excessive alcohol intake. While planning your sleep diet, be sure to include plenty of foods rich in vitamin B6 to keep levels topped up, such as pulses and lentils, liver, oily fish, poultry, bananas, soya foods, beef, lamb and pork.

When to eat before bedtime?

It all depends on lifestyle; how much you eat at mealtimes and what body weight you're trying to achieve. It might be beneficial to eat protein and fibre-rich foods that are satisfying at night, because the evening is when most people scrabble around in the kitchen for snacks. However, some may choose to eat lighter in the evenings, preferring not to feel too full when they go to be