How diet affects your sleep

What you eat and drink can affect every facet of your health, and your quality of sleep is no exception. Research shows there’s a link between disordered sleep and diet.¹

For some of us, a morning coffee is a non-negotiable way to get the day started. If you’re still sipping on lattes into the afternoon or evening, however, you may need to reassess your coffee intake.

Bupa Dietitian Rosalyn D’Angelo says caffeine is a stimulant drug that is strongest in the first hour after having it, but notes it can still be in your system up to 8 hours later.

“Even if you think you can have a coffee before bed and still fall asleep quite easily, it’s possible that caffeine is affecting your sleep patterns throughout the night,” D’Angelo cautions.

Remember that green and black tea, chocolate, cola, energy drinks and cocoa also contain caffeine.

For something hot to drink in the afternoon, try a herbal tea like chamomile, lemon balm, lavender, or peppermint.

Certain foods contain an amino acid called tryptophan, which can be converted into the ‘sleepy hormone’ melatonin. Research shows that a diet low in tryptophan can inhibit sleep.²

“Foods high in tryptophan include turkey, eggs, cheese, seeds, nuts, soy products, milk and yoghurt,” D’Angelo says.

Turkey, chicken and beef contain about 300 milligrams of tryptophan per 85 grams.

Eating regular, balanced meals will not only affect how you feel during the day, but they can also impact your sleep.

“Replacing sugary treats and opting for healthier snacks and balanced meals can promote more stable blood sugar levels, which will likely mean more stable energy levels throughout the day,” D'Angelo explains.

Feeling more energised also means you’re more likely to exercise and handle stress better, which can flow on to better sleep quality.

In a University of Pennsylvania study, scientists found that people who got 7 to 8 hours of sleep a night reported the greatest dietary variety, compared to people who slept too little or too much.³

Going to bed with a rumbling stomach can keep you awake, but so can eating a large meal or consuming rich or spicy food too close to bedtime. This is because these foods can trigger stomach discomfort or reflux.

“I’d encourage people to have their last meal for the day a few hours before they go to bed,” D'Angelo advises.

If you’re still peckish in the late evening, a light snack such as fruit and yoghurt or a few multigrain crackers is a good option.

A glass of wine with dinner may make you feel more relaxed, but that doesn’t translate to better sleep. In fact, it can have the opposite effect.

“Alcohol actually reduces your sleep quality and decreases the amount of deeper restorative sleep you get,” D’Angelo says.

She recommends a gap of at least 3 hours between your last drink and bedtime.

Also, it’s a good idea to stick within the recommended drinking guidelines, which is no more than 10 standard drinks a week and no more than 4 standard drinks on any one day. Pregnant or breastfeeding women should not drink to prevent harm to their child or unborn baby.⁴