How lack of sleep affects your health


Too many Australians aren’t getting enough sleep and it’s costing us our health. Accredited nutritionist Caitlin Reid investigates the health consequences of not getting enough shut-eye.

In today’s fast-paced living, many of us forgo our beauty sleep for hours in front of the computer working or catching up with friends. We sleep less in a bid to get more done, but what we don’t realise is the negative effect this small sacrifice has on our health. Here are the top ways a lack of sleep can play havoc on our health.

1. It promotes weight gain

During sleep, our bodies secrete hormones that help to control appetite, energy metabolism and glucose processing. Sleep loss disrupts the balance of these and other hormones. For example, a lack of sleep increases the production of the stress hormone cortisol, as well as insulin secretion after a meal. Higher levels of insulin are associated with weight gain. Inadequate sleep is also associated with lower levels of hunger-suppressing hormone leptin, as well as higher levels of hunger-promoting ghrelin. As a result, we eat more the next day — as many as 1200 extra kilojoules. For better health, aim for eight hours sleep each night.

2. It increases the risk of developing diabetes

Less than five hours of sleep a night can double your risk of developing type 2 diabetes. Research has found that a lack of sleep reduces insulin sensitivity in the body, meaning more insulin is needed to store the same amount of glucose. One short-term sleep restriction study found that a group of healthy subjects who had their sleep cut back from eight to four hours per night processed glucose more slowly than they did when they were allowed to sleep 12 hours. In addition, researchers have correlated obstructive sleep apnoea — a disorder in which breathing difficulties during sleep lead to frequent arousals — with the development of impaired glucose control similar too that which occurs in people with type 2 diabetes.

3. It increases the risk of developing heart disease

A US study of more than 71,000 women found that having a less than five hours of sleep a night increases the risk of developing heart disease. Too little sleep put the body into an alert state, increasing the production of stress hormones and elevating blood pressure. High blood pressure is a major risk factor for heart disease.

4. It increases the risk of injury

A lack of sleep takes a toll on perception and judgement. It negatively impacts on mood, reduces our ability to focus and our ability to reason. People suffering from insomnia have an increased risk of accidents, as daytime sleepiness increases a worker’s risk of injury. According to the Institutes of Medicine, over one million injuries and between 50,000 and 100,000 deaths each year result from preventable medical errors and many of these may be the result of insufficient sleep. Research shows sleep-deprived people whose occupations involve driving have a higher risk of driving accidents. Thirty-seven per cent of these people nod off at least once on the job during their career. The importance of sleep for performance should not be underestimated.

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