About 15 percent of the country’s primary and secondary school students are overweight, due mainly to bad dietary habits and a lack of exercise, a survey showed Wednesday.

According to the survey conducted by the education ministry of 87,000 students of the country’s 758 elementary, middle and high schools, 14.7 percent were classified as obese, up by 0.4 parentage point from a year earlier.

The ratio of the obese students has been on a constant rise from 11.2 percent in 2008 to 13.2 percent in 2009 and to 14.3 percent in 2010, the survey showed.

“The increasing number of obese students is mainly attributed to bad eating habits as well as the lack of sleeping and exercise,” said a ministry official.

In response to the question of how often they eat fast food, 56.9 percent of elementary school children, 63.5 percent of middle schoolers and 67.7 percent of high school students said they indulge in fast food at least once a week.

In contrast, the number of students who eat vegetables every day came to less than 30 percent on average, according to the survey.

The rate of those who sleep less than six hours per day amounted to 44.7 percent among high school students, 11.9 percent among middle school students, and 4 percent among primary school students.

As for exercise, 51.9 percent of elementary school children met the recommendation of doing a “strenuous workout” three days per week, but the number dropped to 31.4 percent among middle school students and 22 percent among high schoolers.

On average, a male sixth grader is 150.6 centimeters tall and weighs 46.2 kilograms, while a female counterpart is 151.1 centimeters and 44.2 kilograms; a male ninth grader 168.7 centimeters and 61.6 kilograms, with female ninth grader 159.3 centimeters and 53.7 kilograms; and a male 12th grader 173.6 centimeters and 68.4 kilograms, while a female counterpart 160.9 centimeters and 56.2 kilograms, according to the survey. (Yonhap News)