If you want to be brighter, happier and better looking, try getting enough sleep It probably comes as no surprise that HongKongers are among the leading night owls in Asia, with more than half of the population going to bed after midnight on most nights. In this work hard, play hard environment, sleep is often sacrificed for late nights at the office or out on the town. The eight hours of sleep recommended by experts is but a dream for many people, according to surveys by companies such as ACNielsen in Australia. Sleep is vital to maintaining overall health, and a good night's sleep is the most natural way to rejuvenate the mind, restore the body and prepare for the stresses of daily life. During sleep the brain recharges itself by maintaining vital electrical currents, repairing the normal wear and tear of tissues and cells, and preparing muscles for activity and the mind for intellectual and emotional challenges. Inadequate sleep can have a negative impact on the mind and body, and can sabotage performance and health. Mood Waking up after a night of poor sleep is not a happy experience and tends to set the tone for a day of bad tempers, tiredness and lethargy. Because the neurotransmitters in the brain that regulate sleep also control our moods, the connection between good sleep and overall happiness is undeniable. When cerebral transmitters become lethargic and need to be restored through sleep, irritability is often the result. Long-term lack of sleep can result in routine moodiness and depression that can affect our quality of life. Studies on insomniacs and the sleep-deprived have shown that their moods improve dramatically once they get enough sleep. Mental sharpness Memory and concentration, two vital components of professional productivity, are related to good sleep. Lack of sleep interferes with the chemical and neurological processes in our brains that help us remember. Sleep-deprived individuals tend to perform significantly worse on memory tests than those who have a history of getting enough sleep. Drowsiness, which reduces the ability to concentrate, hinders perception and decision-making. Pulling all-nighters to impress the boss will eventually backfire. Immune system Besides affecting our moods, emotions and mental acumen, studies have shown a connection between sleep and disease prevention. Getting enough sleep is critical for boosting the immune system. When we sleep, our bodies go through internal processes that bolster their defence mechanisms. People who do not get enough sleep compromise their immune defences and are more prone to getting bacterial and viral infections. Weight control Good sleep is also linked to weight control. Studies have shown that a lack of sleep affects hormones that control the appetite, causing the sleep-deprived to feel hungry even when they have had enough to eat. Other studies have shown that people who get too much or too little sleep have an increased incidence of diabetes compared with those who sleep seven to eight hours a night. Physical appearance Cosmetic companies have cashed in on the need for creams, gels and face masks to deal with dark circles under the eyes. During sleep the body repairs and regenerates the skin, blood and muscle cells, improving skin tone, flushing out toxins and replacing dead cells that make the skin look dull. (There is a reason it is called beauty sleep.) Think of sleep as an important bank account with a required minimum balance. Once the balance is reached, results are immediate in terms of improvement in mood, performance and overall health.