Japanese high school students have lower physical and mental self-confidence but healthier eating habits than their American, Chinese and South Korean counterparts, according to a study released Friday by the National Institution for Youth Education.

The NIYE, a semipublic body, collectively surveyed 8,480 high school students in China, South Korea, the United States and Japan last year about their mental and physical condition, asking them to evaluate themselves on their daily lifestyle, including eating and exercise habits.

Asked if they considered themselves a valuable person, 44.9 percent of Japanese said yes to some extent, compared with 83.8 percent of the American students, 83.7 percent of the Koreans and 80.2 percent of the Chinese.