Eating just before sleeping — will it affect your sleep?

Monday, March 5, 2007
When you come home after a night out and tuck into a spicy curry it tastes great — but the after-effects may not be so good. There's a theory that eating a heavy meal right before hitting the sack will leave you tossing and turning all night.

Chances are that curry will cost you a good night's sleep. But does what and when you eat really affect the quality of your sleep?

That's what we're putting to the test.

The test

Our experiment has taken place at the Centre for Sleep Research at the University of South Australia where Professor Drew Dawson is Dean.

So what does he think about the idea that eating before bedtime will mess up your shuteye?

"It depends on what is in the meal and what time you eat that meal before you go to sleep," he says.

Let's put that to the test. Meet Phoebe, Kurt, Alex and Leigh — our sleeping partners in this test.

Their first task is dinner. Alex and Kurt tuck into their meal now (three hours before bedtime). Phoebe and Leigh get exactly the same dish but it's a take-away, which they'll have to wait for until just before going to bed.

At the lab, sleep technician Sarah Biggs gets all four wired up.

"First thing we're going to do is put an electrode right in the middle of [the] head which we call a reference electrode. That just helps us to read the signals from your brain activity," says Sarah.

This hard wiring feeds into computers that allow Sarah to monitor our volunteers as they sleep. It shows brain patterns, eye movements and even teeth grinding.

What about Phoebe and Leigh? They're both dying to get their hands on that takeaway.

"It's a little bit different to what I'd normally do. Normally I eat a few hours before I go to sleep — but we'll wait and see what happens in the morning I guess," says Leigh.

Dinner tastes great, but will it feel so good sitting on their stomach as they try to sleep? It's lights out for our four sleepyheads.

But Sarah's maintaining an all night vigil — she'll be recording every second of their sleep over the next eight hours and in the morning we'll find out if our late eaters got a worse night's sleep than our early eaters.


The next morning …

How did they all sleep? Both our early eaters slept well but what about when it came to the late eaters?

Leigh: "I tossed and turned a lot, it took me a little while to get to sleep. Obviously I slept a bit because it went a bit faster than I thought but yeah not very well at all. Normally I sleep like a little baby so it was a bit of a change last night."

Phoebe: "I feel like I was tossing and turning all night and I've got to go to uni now so I'm probably not going to be performing at my best."

So, what part of the night's sleep did our late eaters miss out on?

There are five stages of sleep:

  • Stage one: drowsiness
  • Stage two: light sleep
  • Stages three and four: deep sleep
  • Stage five: REM

Deep sleep is when the body rests and repairs itself ready for another day. And that deep sleep is what our late eaters missed, especially in the early part of the night.

"They had a lot more awakenings and a lot more movement than the early eaters so they didn't actually get a lot of the deep sleep that is normally associated with the early hours of the night," says Sarah Biggs.

The results of our test are no surprise to Professor Drew Dawson.

"This is what we would expect based on what we've seen in the literature before," he says.

Dr Clare Collins, a lecturer in nutrition at the University of Newcastle, agrees. She says the body simply isn't designed to cope with a heavy load before sleep.

"If you have a really full stomach and you lie down, you're more likely to get a bit of reflux. You've got your digestion cranked up at full speed when your body should actually be relaxed, calm — more to help you get a really good night's sleep," she says.

Being hungry is as disruptive to sleep as being too full. A light snack one hour before bed can help fuel your body for rest. But not just any snack.

"The ideal mix of foods for a really good night's sleep are going to be some carbohydrate foods, preferably the wholegrain versions of those, and then some protein foods — but just a small amount. Now a really good example of that would be something like a banana with a glass of milk, a slice of toast with a small amount of cheese or turkey on top," says Dr Collins.

Why this combination of foods?

If we look at the milk and bananas combo, milk has amino acids. In the brain that's converted to serotonin — a calming hormone. Bananas have carbs. When you add carbs to the amino acids it boosts the serotonin levels in the brain. That's important because serotonin becomes melatonin — the hormone that triggers sleep.


So here are our top tips for a good night's sleep:

  • Eat dinner several hours before bed
  • Eat a light, low-kilojoule supper of protein and complex carbohydrates one hour before sleep.
  • No coffee
  • No alcohol

So if you don't want to be grumpy the next day, then give those late-night curries a miss — you'll thank us in the morning!

Fast facts

  • One of the age-old beliefs is that eating cheese before bed will give you nightmares. But is it true and do different cheeses have different effects? Well, British researchers gave 200 people cheese every night for a week before bed. No one had a nightmare but it did affect their dreams. People who ate cheddar dreamt about celebrities. While another British cheese, Red Leicester sent people back to their schooldays.

  • Some people say eating just before going to bed makes you fat because the body doesn't need the energy while you're asleep. True or false? False. What counts is how many kilojoules you eat in a day — you put on weight when you consume more energy than you expend.

A weight-loss revolution? Beating the mid-afternoon slump Body beautiful: alternative ways to tone up How to tell when someone's lying