Anna Millar: A poor night's sleep doesn't just make you tired, it could also be making you fatter and less inteligent

THE alarm goes off, you fall out of bed and, chances are, you reach for your first caffeine hit of the day. Still slightly dopey, you're already exhausted just thinking about the endless to-do list that lies ahead. If this sounds familiar, you're not alone.

Recent studies suggest we're sleeping less, and worse, than ever before. And as if the general 'can't sleep/won't sleep' phenomenon wasn't enough, a new book suggests that not only does sleep deprivation cause general lethargy and stress in your life, it's also likely to make you fatter and less intelligent, with even a little sleeplessness leading to tighter jeans and a serious dip in cognitive function.

According to brain expert and author of Change Your Brain, Change Your Body, Dr Daniel Amen, it has become an epidemic: "In our hectic, 24/7 society, I could just as easily ask: "What doesn't cause sleep deprivation?" There is a seemingly endless number of reasons why millions of us are missing out on a good night's sleep."

Hide Ad

Dr Amen believes getting a sufficient amount of rest is vital for the body to repair itself. "Sleep is so critical to brain function, yet the way we approach sleep has changed radically in recent years. We used to get nine hours and now, on average, people are getting six and half. You can't go through that level of change for it not to have a negative consequence.

"Good sleep is essential for optimal brain and body health. It's involved in rejuvenating all the cells in your body and gives brain cells a chance to repair themselves." Dr Amen is not the only one noting a trend. Research suggests bad sleep or lack of sleep can lead to a Groundhog Day scenario. Tiredness during, and after, a long day, leads us to opt for the easy option, ducking out of exercise classes, stocking up on poor nutrition meals and even cancelling social outings with friends and family.

When we feel sleep deprived, managing our diet can be a tricky beast, with research from Bristol University suggesting people who habitually sleep for five hours have 15 per cent more ghrelin, the hormone that increases feelings of hunger, than those who sleep for eight hours.

We are essentially a machine and need to be oiled properly. Our temperature, hormone and brain chemistry work on a 24-hour clock. When we mistreat or tamper with our regular sleep cycle - or worse, don't have a regular cycle at all - our bodies and mind are affected, with bad food choices hampering the brain's ability to process information as effectively as it should.

"We have such a lot of bad habits now," says Dr Amen."Alcohol, sleeping pills and caffeine are all chemically altering our bodies, while junk food works on the 'heroin' centres of your brain making you crave it even more."

A study published in the American Journal of Clinical Nutrition found that when people slept only five and a half hours, they consumed an average of 221 more calories in high-carbohydrate snacks than when they got eight and a half hours of sleep.

Hide Ad

And it's not just a weight issue. Those who get less than seven hours a night have lower activity in the prefrontal cortex and temporal lobes, says Amen, which helps memory and learning. This limits their ability to pay attention, learn, solve problems and remember important information.

Research suggests relationships can also become strained, with a 2007 survey from the Better Sleep Council revealing that 44 per cent of workers questioned said they were more likely to be unfriendly, unpleasant and unable to concentrate if they had been deprived a decent night's sleep.

Hide Ad

Making concerted changes to your life is the first step, says Dr Amen: "Do your best to eliminate things that distract you. Keep laptops, phones and televisions out of the bedroom, and if you do use them in the evening give yourself between one hour and two to wind down.

"If you read before sleep, pick your book wisely and opt for nothing that might leave you feeling unsettled.

"While exercise at night can be positive for your health, don't go too hard at it too close to bedtime, as your body will still be revving up when it should be shutting down. Try not to eat for at least three hours before bed. Lay off caffeine, alcohol and nicotine."

Ultimately, says Dr Amen, most people know what they need to do when it comes to sleeping habits: "Sleep is absolutely vital to how we live our lives; people need to recognise what they need to do and start doing it." n

• Change Your Brain, Change Your Body is published 6 January 2011, Piatkus, 12.99