Regular poor sleep puts you at risk of serious medical conditions, including obesity, heart disease and diabetes – and it shortens your life expectancy.
“Because we found that adults who reported sleeping less than their peers were more likely to be overweight or obese, our findings highlight the importance of getting enough sleep,” said the study’s senior investigator, Laura Hardie, of the University of Leeds in England.
“How much sleep we need differs between people, but the current consensus is that seven to nine hours is best for most adults,” Hardie said in a university news release.
For the study, the research team looked at more than 1,600 adults in the United Kingdom. The participants reported how long they slept and kept records of what they ate. The participants also had blood samples taken and their weight, waist circumference and blood pressure measured.
The waists of those who slept an average of six hours a night were more than an inch larger than those who slept nine hours a night, the finding showed.
People who got less sleep also weighed more, and had reduced levels of HDL “good” cholesterol in their blood, which can cause health problems, according to the study authors.
However, the researchers found no link between shortened sleep and a less healthy diet.
The results were published online July 27 in the journal PLoS One.
According to study co-author Greg Potter, “The number of people with obesity worldwide has more than doubled since 1980. Obesity contributes to the development of many diseases, most notably type 2 diabetes. Understanding why people gain weight has crucial implications for public health.”
The study can’t show a direct cause-and-effect relationship between less sleep and weight gain. Still, the findings add to the growing body of evidence about the link between sleep and health, the researchers said.
Most of us need around eight hours of good-quality sleep a night to function properly – but some need more and some less. What matters is that you find out how much sleep you need and then try to achieve it.
As a general rule, if you wake up tired and spend the day longing for a chance to have a nap, it’s likely that you’re not getting enough sleep.
A variety of factors can cause poor sleep, including health conditions such as sleep apnoea. But in most cases, it’s due to bad sleeping habits.
Find out the common medical causes of fatigue.
Everyone’s experienced the fatigue, short temper and lack of focus that often follow a poor night’s sleep.
An occasional night without sleep makes you feel tired and irritable the next day, but it won’t harm your health.
After several sleepless nights, the mental effects become more serious. Your brain will fog, making it difficult to concentrate and make decisions. You’ll start to feel down, and may fall asleep during the day. Your risk of injury and accidents at home, work and on the road also increases.
Find out how to tell if you’re too tired to drive.
If it continues, lack of sleep can affect your overall health and make you prone to serious medical conditions, such as obesity, heart disease, high blood pressure and diabetes.
Here are seven ways in which a good night’s sleep can boost your health:
If you seem to catch every cold and flu that’s going around, your bedtime could be to blame. Prolonged lack of sleep can disrupt your immune system, so you’re less able to fend off bugs.
Sleeping less may mean you put on weight! Studies have shown that people who sleep less than seven hours a day tend to gain more weight and have a higher risk of becoming obese than those who get seven hours of slumber.
It’s believed to be because sleep-deprived people have reduced levels of leptin (the chemical that makes you feel full) and increased levels of ghrelin (the hunger-stimulating hormone).
Given that a single sleepless night can make you irritable and moody the following day, it’s not surprising that chronic sleep debt may lead to long-term mood disorders like depression and anxiety.
When people with anxiety or depression were surveyed to calculate their sleeping habits, it turned out that most of them slept for less than six hours a night.
Studies have suggested that people who usually sleep less than five hours a night have an increased risk of having or developing diabetes.
It seems that missing out on deep sleep may lead to type 2 diabetes by changing the way the body processes glucose – the high-energy carbohydrate that cells use for fuel.
Men and women who don’t get enough quality sleep have lower libidos and less of an interest in sex, research shows.
Men who suffer from sleep apnoea – a disorder in which breathing difficulties lead to interrupted sleep – also tend to have lower testosterone levels, which can lower libido.
Long-standing sleep deprivation seems to be associated with increased heart rate, an increase in blood pressure and higher levels of certain chemicals linked with inflammation, which may put extra strain on your heart.
Difficulty conceiving a baby has been claimed as one of the effects of sleep deprivation, in both men and women. Apparently, regular sleep disruptions can cause trouble conceiving by reducing the secretion of reproductive hormones.
If you don’t get enough sleep, there’s only one way to compensate – getting more sleep.
It won’t happen with a single early night. If you’ve had months of restricted sleep, you’ll have built up a significant sleep debt, so expect recovery to take several weeks.
Starting on a weekend, try to add on an extra hour or two of sleep a night. The way to do this is to go to bed when you’re tired, and allow your body to wake you in the morning (no alarm clocks allowed!).
Expect to sleep for upwards of 10 hours a night at first. After a while, the amount of time you sleep will gradually decrease to a normal level.
Don’t rely on caffeine or energy drinks as a short-term pick-me-up. They may boost your energy and concentration temporarily, but can disrupt your sleep patterns even further in the long term