TOKYO -- Obsessed with looking slim, one in 20 junior high school girls in Tokyo suffers from anorexia nervosa, an eating disorder caused by stress, a Japanese government-funded survey showed on Saturday.

Most Japanese teenage girls are obsessed with losing weight, skipping regular meals and snacking on biscuits, eager to fit into the tight jeans and pencil-thin skirts that are the fashion. Magazines on diets for teenagers are very popular.

A three-year survey of 219 high school girls aged from 14 to 15, conducted by a research group and funded by the Health Ministry, showed 5.6 percent of those who graduated in 1987 had anorexia.

It said 6.7 percent of those girls who graduated in 1992 had similar symptoms and 5.5 percent in 1997.

The survey showed that about one in four third-grade girls at senior high schools, aged between 17 and 18, had an "unhealthy" body weight.

The eating disorder, caused by various factors such as media exposure to unrealistic body images, social pressure, stress and academic strain, occurs mainly in adolescent girls.

Experts said only about one in 100 Japanese adolescent girls suffered from the eating disorder, but warned that the number of such sufferers had been increasing rapidly in recent years in Japan, the United States and Europe.