So far, the 6,000 people who have participated in the program have lost a combined 40,000 kilograms - an average of less than 7 kg apiece.

In a worldwide shift of strategy, Weight Watchers is recalibrating its programs to appeal to men as well as women - in the past, the approach was too "feminized," Rosengarten says.

He expects to see a dramatic change in attitudes toward health in the next few years, as those aged 45 and over begin to develop chronic diseases and those approaching middle-age learn from their example.

"They will say that they do not want to be like the 45-plus group and will start taking action. That will open up a new, big opportunity for Weight Watchers," Rosengarten says.

Growing awareness

While many Chinese are still enamored of their newly comfortable lifestyles, there is a growing recognition of the hazards of weight gain, both for the young and old, especially given that Chinese appear predisposed to suffer from diabetes more easily than some other populations.

A study led by researchers at the University of North Carolina found in July this year that the rate of diabetes among Chinese teenagers was nearly four times higher than among those in the US. The risk factor for heart disease was 50 percent higher among Chinese teenagers than for their American peers.

Barry Popkin, a professor of nutrition at UNC's Gillings School of Global Public Health who led the study, said in a statement, "What is unprecedented is the change in diet, weight and cardiovascular risk for children aged seven or older."

While many older Chinese have also grown fatter, most still shun Western fast foods, favoring a more traditional diet, albeit one much heavier in fats and meats than a generation ago.

But many children have grown accustomed to dining on Kentucky Fried Chicken, McDonalds and snack foods.

"China's health care system will face a huge burden if nothing changes," said Popkin, "Already, 1.7 million Chinese children aged seven to 18 have diabetes and another 27.7 million are considered prediabetic. In addition, one-third of children under age 18 had high levels of at least one cardio-metabolic risk factor."

Given these facts of life, convincing Chinese who already work long hours and endure lengthy commutes to add an hour's exercise to their already busy schedules is a tough sell, especially given the lack of adequate public recreation facilities.

China's middle class, and those aspiring to join them, are still too focused on pursuing economic gains.