Claims that authorities were ignoring the plummeting standards of youth health followed a national survey showing one in four boys in China's cities was clinically overweight or obese.

The survey published by the Ministry of Education has been conducted four times on nearly 1.6 million urban students since 1985.

The obesity rate of Beijing students last year rose by 50 percent from 2000, and 52 percent had poor eyesight.

Fifty-eight percent of middle school students were short-sighted, with the rate rising to 76 percent of high school students and 83 percent of college students.

In Beijing, more than half of the middle school students were found to have abnormally high blood pressure and more than 60 percent of high school students had the same problem, according to another survey launched in 2005.

"Their joints are seizing up, their muscles are becoming flabby and their movements are uncoordinated due to lack of exercise," said Mao Zhenming, head of the School of Physical Education and Sports Science of the Beijing Normal University.

Yang Guiren, director of the Sports, Health and Arts Department of the Ministry of Education, attributed the deterioration to modern lifestyles, where urban dwellers eschew the stairs for the lift, travel by car and do little physical labor.

However, the exam-oriented education system, in which students studied for long hours with little exercise time, was also to blame.

Some experts believe poor public awareness of the necessity of physical exercise and the harm of obesity are obstacles to improving youngsters' health.

Many parents paid too much attention to their children's studies, believing exercise to be waste of time, said an expert with the Healthcare Institute for Primary and Middle School Students in Taiyuan City, capital of north China's Shanxi Province.

Moreover, many parents believed improved living standards automatically led to a better diet and healthy growth, allowing children to eat high-calorie foods, the expert said.

"My son likes KFC and McDonald's very much and I take him there as a reward for getting good exam marks," said parent Gao Guizhen.

However, Gao was unaware of the unhealthy effects of junk food. "It is so popular among the children.... They should be okay."

The problem is exacerbated by a shortage of trained P.E. teachers and facilities in schools, which limits the access of students to proper physical exercise.

"The number of P.E. teachers in China, about 370,000, is far from enough to meet the needs of students, especially in western regions," said Yang.

Most schools in western regions had few facilities that meet national standards and some even lacked adequate playgrounds, he said.

Last November in Qinyuan County, Shanxi Province, 19 students and a teacher were killed by a truck when they were jogging along a highway. One of the causes of the tragedy was their school did not have proper running tracks on the campus.

Wang Xiaowei, a P.E. teacher at the Taiyuan University of Technology, said the general content of P.E. class was unpopular with students.

Compared with on-line games and other modern attractions, P.E. classes seemed boring and outdated. "They would rather spend time in Internet bars than on the playground," he said.

"More varied programs targeting the features and interests of students at different ages should be introduced to the P.E. class, " Wang said.

Physical deterioration also triggered mental problems, said Mao Zhenming, who worried that China's youth would lack the physical and mental faculties needed to compete in the future.

The government had realized the situation and taken measures, said Yang. In 2000, the Ministry of Education reformed the curriculum in primary and middle schools, adding another hour to P.E. time.

As a result, the first to third graders in primary schools had four classes of P.E. (about 40 minutes each class) every week, the fourth graders up had three classes.

The proportion of P.E. in overall high school credits had also been raised.

In order to ease the staff shortage pressure, the ministry had improved pay and insurance to attract college graduates who majored in sports to train as P.E. teachers.

Meanwhile, the ministry was considering recruiting part-time P.E. teachers from other subjects with short-term training, said Yang.

Developed regions were being required to list obesity as a common illness in school disease control plans with targeted high-risk groups of primary and middle school students, said health expert Ji Chengye.

The underdeveloped regions needed to control obesity and malnutrition at the same time, said Ji, a professor in Peking University.