"What we are seeing is the emergence of what we are calling Asia's Generation O - a demographic that is overworked, overstressed and generally overwhelmed," Sun Life Hong Kong chief executive Wim Hekstra said yesterday.

"The malaise is especially evident in Hong Kong."

The poll was conducted online for insurer Sun Life Financial by market-research firm Ipsos in August and last month.

Researchers drew their findings from more than 5,000 people aged 25 to 55 in Hong Kong, mainland China, Indonesia, Malaysia, the Philippines, Singapore, Thailand and Vietnam.

Only 22 per cent of Hongkongers were content with the air quality, the lowest among the eight regions, which averaged 41 per cent, according to the poll.

About 26 per cent reported that the filthy air caused them respiratory problems, compared with 23 per cent on the mainland.

Hongkongers who were satisfied with their mental and physical health made up 43 per cent and 46 per cent of local respondents, compared with the regional average of 64 per cent and 62 per cent, respectively.

About 51 per cent said they led healthy lives, compared with 72 per cent across the eight regions.

Hongkongers and Singaporeans were the most dissatisfied with their stress and exercise levels, according to the research.

Joe Leung Cho-bun, professor of sociology at the University of Hong Kong, suggested the ingrained culture of devoting one's entire life to working to earn as much money as possible was one of the reasons Hongkongers were so stressed out.

Young people were aspiring to get good jobs amid a highly competitive society, he noted.

"The stress can affect their mental and physical health," Leung said. "They may take drugs, suffer from insomnia or rely on alcohol as a result."

Respondents who admitted not having a healthy or active lifestyle cited reasons including a lack of time due to work, a lack of personal motivation and the distractions of television and the internet.