IT'S ALMOST MIDNIGHT in Hong Kong, a time when, according to the rules of nature, everyone should be safely tucked up in bed. But look around and people are behaving as if the day had only just begun, shopping for groceries, working on their computers or even at the gym.
In our 24-hour society, night time is no longer reserved for sleep. It's become the new daytime, offering us the chance to catch up on everything we didn't manage to cram in during the day.
Such flexibility comes at a high price, however, because many Hongkongers simply aren't getting enough sleep. 'People are trying to compress their sleep because they want to spend more time working, having fun or going out,' says Dr Wing Yun-kwok, associate professor of psychiatry at the Chinese University, who is head of the Sleep Assessment Unit at Sha Tin Hospital.
And it's not just our 24/7 lifestyle that's robbing us of shut-eye. 'The high population density in Hong Kong increases the level of brightness at night, and the houses are so tightly packed together that you're very lucky if you're not disturbed by your neighbours,' says Professor Pang Shiu-fun, vice-president and chief technology officer at CK Life Sciences International (Holdings) and an expert on the sleep hormone melatonin.
A recent Chinese University study found that about 20 per cent of the population feels constantly sleep deprived, with 20- to 30-year-olds the worst affected. And last year, a study by the University of Hong Kong found that 92 per cent of Hongkongers have experienced one or more sleep deprivation symptoms, including sleeping late at weekends, needing an alarm clock to wake up, falling asleep while watching TV and, more worryingly, feeling drowsy while driving.
Sleep deprivation is an increasingly common problem throughout the commercialised world. Researchers say we're sleeping less than a century ago.