How did you sleep last night – tossing and turning restlessly in the small hours? Well yesterday’s dinner, or even breakfast, could be to blame for your bleary eyes today.
Scientists have found that our diet directly affects how well we sleep – and the resulting advice is nowhere near as obvious as simply avoiding that extra coffee before bedtime.
A study published in the journal Appetite found big differences in the diets of people who slept the longest number of hours compared with those snoozing for the least.
Those who slept less than five hours drank less water, took in less vitamin C, had less selenium, which is found in nuts, meat and shellfish, but ate more green, leafy vegetables.
Longer sleep was associated with consuming more carbohydrates, less choline, which is found in eggs and fatty meats, and less chocolate and tea.
Nutritionist Linda Foster says: “It makes perfect sense that our diet can affect our sleep quality.
“Some foods such as bananas contain high levels of tryptophan, an amino acid that makes you sleepy, so they can be a great help in combating insomnia.
“From a medical standpoint, we know that deficiencies of key minerals such as calcium and magnesium are linked to certain sleep disorders.”
And while everyone knows that eating a large meal before bed is a bad idea if you want a good night’s kip, scientists have now pinpointed that avoiding food for three hours before bed is optimum, as it lets your body go into wind-down mode and release the sleep-promoting hormone melatonin.
Research also dispelled the old wives’ tale that eating cheese at night can keep you awake or trigger bad dreams.
In fact, in one study, three-quarters of volunteers who were fed a 20g piece of cheese every night before bed reported that they slept very well.
So if sleep has been hard to come by of late and medical causes have been ruled out, it’s well worth taking a long, hard look at your diet.
The food-sleep cycle
In the last few years, the link between what we eat and our sleep patterns has emerged as an important piece in the obesity puzzle.
Not only can the right food aid sleep, it works the other way too – better sleep promotes weight loss.
Lack of sleep, however, has been found to stimulate production of hunger hormone ghrelin, which makes us overeat.
Evidence shows that the more sleep you get, the fewer calories you eat the next day.
A German study last year showed that after just one night of disruption, volunteers were less energetic and used fewer calories, but were hungrier and ate more – a recipe for weight gain.
This means eating the right foods for a better night’s sleep is a win-win solution.
It will help you sleep, which in turn should keep you trim. So can you eat your way to sounder sleep?
Best bedtime snacks
The ideal pre-snooze nibbles are small enough that they won’t need a lot of digestion, but rich in carbs to boost sleep-inducing serotonin levels.
Good picks include:
- A bowl of porridge made with milk and a chopped banana
- Granary toast with peanut butter
- Wholemeal pitta bread with houmous
- A glass of warm milk
Top 10 sleep tight tricks
1 Eat little and often
Having something nutritious every few hours helps your body and brain maintain the right balance of hormones and neurotransmitters, essential for falling – and staying – asleep at night. Rather than large meals with gaps in between, aim for six mini meals a day.
If you go to bed hungry, your body’s innate biological need for food will send signals to keep you awake to find subsistence – a survival throwback to our cavemen days when food was scarce. So a small snack is better than nothing.
2 Eat early
Avoid eating your evening meal any later than three hours before bed, as this will optimise your blood sugar and melatonin levels.
Eating a big meal increases the blood flow to your digestive tract, causing your stomach to secrete more gastric acid and making your intestinal muscles work harder. This stimulates your body’s metabolic systems at the very time when you want them to be slowing down.
Some studies even suggest that eating too close to bedtime, or very late at night when you’d normally be sleeping, may throw your body’s internal clock into confusion and lead to overeating and weight gain.
Avoiding large late meals also reduces reflux, when stomach acids rise up into the oesophagus, which can be a serious sleep disrupter. Indeed, US research suggests that that up to 25% of people who report bad sleep without a diagnosed cause actually have acid reflux without realising it.
3 Go bananas
Have a banana – ideally in the second half of the day.
This sleep wonder fruit is packed with potassium and magnesium, nutrients that double as natural muscle relaxants.
Plus, they contain the sleep-inducing amino acid tryptophan, which ultimately turns into serotonin and melatonin in the brain.
Serotonin is a natural chemical that promotes relaxation, while melatonin is the hormone that promotes sleepiness.
4 Have a carb-rich dinner
A recent study at The University of Sydney, Australia, found that people who ate rice before bedtime fell asleep faster than those who didn’t as rice is rich in sugars, which increase production of tryptophan, the amino acid that makes you sleepy.
Bread, pasta and cereal can have the same effect.
5 Avoid fatty meals
Not only will greasy takeaways scupper your diet, they’re a recipe for sleep disaster.
Research suggests people who have fatty meals in the evening clock fewer hours of total sleep than those who don’t, so stick to lean meat and plenty of veg.
6 But don’t crash-diet
If you’re eating fewer than 1,200 calories a day, as many diets recommend, there’s a good chance you’re missing out on key nutrients, which can seriously affect your sleep.
Low levels of calcium, from dairy products, and magnesium, which is found in green veg and nuts, are linked to poor sleep, as both are natural relaxants.
Low iron can trigger restless leg syndrome symptoms in which twitching leg movements disrupt your sleep.
A deficiency in the B vitamin, folic acid, found in wholegrains and green leafy veg, may also lead to insomnia.
People who don’t get much vitamin C – in fruit and veg – or selenium from nuts, meat and fish have been shown to sleep for fewer hours.
The answer? Follow a healthy, varied diet rich in fruit and veg, wholegrains, low-fat dairy, nuts, fish and lean red meat to ensure a good supply of vital nutrients.
7 Lay off the booze
Initially drinking induces sleep, but if you indulge in more than one or two small drinks you’re in for a fragmented night.
One recent study showed alcohol increased slow-wave deep sleep in the first half of the night, but increased sleep disruptions in the second half – thus wiping out all the earlier benefits!
8 Watch the salt
Processed foods such as ready meals and even many breads and soups contain a lot of sodium, which can interrupt sleep by raising your blood pressure and dehydrating you.
9 Drink plenty of water
Research shows the more hydrated you are, the more hours kip you get.
Aim to drink around six to eight glasses of water a day.
But if getting up for the loo disrupts your sleep, avoid liquids for three hours before bedtime.
10 Skip coffee
People often stop drinking coffee at lunchtime, but experiments shows that caffeine stays in your system for up to 12 hours – an 11am latte could linger until 11pm.
Avoiding caffeine for one day, on the other hand, can improve sleep quality that night, according to a study in the Journal of Clinical Nursing.
Even chocolate and tea, which contain the stimulant theobromine, have been shown to disrupt sleep and may be best avoided.