Marcela Fiuza, a dietician and spokesperson from the British Dietetics Association, tells HuffPost UK that tryptophan – an amino acid found in protein foods – is thought to promote sleep.
“Tryptophan is a precursor of the sleep-inducing chemicals serotonin and melatonin,” she explains. “The best sources are eggs, poultry, meat, fish and cheese.”
Tryptophan is most effective when consumed alongside carbohydrate foods such as bread, potatoes and cereals, Fiuza adds. “Although more research is needed, if you struggle to sleep you could try a small protein and carbohydrate snack in the evening such as cheese and crackers or poached egg on a slice of toast, or a high tryptophan evening meal including turkey or chicken,” she says.
A glass of warm milk, which contains tryptophan, is often recommended as a sleep aid – but Drew Dawson, a sleep and fatigue expert and at Central Queensland University, previously told HuffPost Australia the effectiveness is largely an old wives’ tale.
He said the tryptophan content in milk is so low, it probably won’t make a difference to most people. There’s also no scientific evidence that warming milk has an impact – but that doesn’t mean we should dismiss it altogether.
“The routine of drinking a glass of warm milk may elicit memories of mum, home and childhood, which may help us to relax,” he said.
Some types of food and drink prohibit sleep, so should be limited during the day and avoided before bed, says Fiuza.
Caffeine acts as a stimulant both mentally and physically, she explains, so if you have trouble sleeping, cut down the amount of caffeine you have – and don’t have any for at least four hours before bedtime.
Although alcohol may make you feel a little drowsy at first, drinking booze is associated with more frequent awakening, nightmares, and a less restful sleep through the night. “It can also affect melatonin levels and interferes with your circadian rhythm,” Fiuza says.
There’s also evidence that eating spicy food before bed can negatively impact your sleep. A study published in the International Journal of Psychophysiology found that when healthy individuals ate a meal with tabasco before bed, they had elevated body temperatures and took longer to fall asleep than when they didn’t have spicy food.
The best time of day to eat dinner will depend on your own routine – and can be particularly hard to figure out if you do shift work. But as a general rule of thumb, going to bed too full, or hungry, may prevent you from nodding off.
Avoid finishing big meals two to three hours before bed where possible. Fiuza also recommends avoiding large beverages in the run-up to bedtime, which should limit sleep disturbance caused by trips to the loo.
If you’re really struggling to head to the land of nod, Fuiza adds that you should talk to your doctor before taking any herbal or dietary sleep aids as these can interact with other medication.