Get enough sleep

Wednesday, July 29, 2009

Get enough sleep

Lack of rest ups ghrelin, a 'hunger hormone' that stimulates one's appetite

Eveline Gan

THE benefits of a good night's sleep go beyond improving your concentration and overall well-being. Researchers have found that it is also good for your waistline.

Those who consistently fail to get enough sleep may experience weight gain, according to findings presented at Sleep 2009 in Seattle last month. The annual meeting of the Associated Professional Sleep Societies is attended by doctors, researchers and healthcare professionals.

A study on 92 healthy adults conducted by University of Pennsylvania found that those who had less than the average amount of sleep gained an average of 1.3kg during the 11-day experiment.

Another study on 1,000 volunteers conducted by Stanford University in California found that those who slept less than eight hours a night had higher levels of body fat. Those who reportedly slept the least weighed the most.

The findings are hardly surprisingly, since inadequate sleep affects the hormones that help control our appetite and metabolism, said local sleep specialist Dr Lim Li Ling.

According to Dr Lim, who is the director of Sleep Disorders Unit at Singapore General Hospital, sleep deprivation is "a stressful state which alters our body's hormonal environment".

Getting a good night's rest may also be good for your waistline.

Lack of sleep decreases the level of leptin, a hormone that makes one feel full after eating. It also increases the level ghrelin, a "hunger hormone" that stimulates one's appetite. This results in overeating and weight gain, said Dr Lim.

"People who don't get enough sleep may also feel tired and exercise less," she added.

For those who have less sleep because they stay up late, eating habits such as bingeing on calorie-laden foods to stay awake may be the reason behind the weight gain, said Ms Lim Su Lin, chief dietitian and senior manager at National University Hospital's dietetics department.

"To stay awake, they may resort to drinking high-sugar, caffeinated beverages or munching on tidbits," said Ms Lim. They may pile on the pounds as a result.

To control your appetite through the day, Ms Lim recommended sticking to three main meals a day at fixed times, and including fibre to your meals.

Fibre, which can be found in vegetables, fruits and whole grains, makes you feel full and thus deters snacking. Starting the day with a wholesome breakfast can also help you avoid binge eating later in the day.

For another group of people, the problem may be more serious than weight gain.

A substantial number of Singaporeans suffer from sleep disorders. Dr Lim estimated that 10 to 30 per cent of the local population have insomnia and up to 15 per cent have obstructive sleep apnea (OSA).

OSA is a condition where a person's upper airways are blocked during sleep. "When breathing is interrupted during sleep, the quality of sleep is affected," she said. Poor sleep is known to be as detrimental as lack of sleep.

So what constitutes a good night's sleep?

"It is simply one from which we wake up naturally (without an alarm clock), feeling refreshed, alert and able to function at peak mental performance," said Dr Lim. A person who sleeps well would not need to nap in the middle of the day.

The amount of sleep a person requires varies with age. According to Dr Lim, newborns may need as much as 16 to 20 hours, spread throughout the day, while young children should get 9 to 10 hours and teenagers, 8 to 9.5 hours.

Adults require 6 to 10 hours of sleep.

"Although some people take pride in getting by with very little sleep, most people who get fewer than five to six hours daily are probably not getting enough," said Dr Lim.
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How to achieve a good night's rest
A guide to a good night's sleep - by Dr Lim Li Ling, director of Sleep Disorders Unit at Singapore General Hospital.

Try to go to bed and wake up at around the same time. Our sleep-wake patterns are regulated by an internal "clock" that dictates when we feel sleepy. When our daily activities synchronise with our internal clocks, we will naturally sleep better.

If you can't fall asleep within 15 to 20 minutes, leave the bedroom and do something relaxing, such as reading or listening to soft music. You should only return to bed when you feel sleepy again, however long it takes.

If you have insomnia, you should not read, watch TV or work in bed. Associating the bed with other types of activities, especially if they are stimulating, will make it harder to fall asleep.

Avoid caffeine - a stimulant that can stay in your body for over 10 hours - and stimulating activities close to bedtime. Stimulating activities include vigorous exercise, intense work and exciting TV programmes.

Long afternoon naps make it difficult for us to fall asleep at night and should be avoided.

A daily ritual to help us relax at the end of the day is a good lead-up to sleep. This can take the form of a taking a warm bath, dimming the lights, reading quietly or listening to soft music.

From TODAY, Business – Monday, 27-Jul-2009