• body mass index;
  • eating disorders;
  • Japan;
  • young females

The height, weight and body mass index (BMI) of Japanese males and females aged from 6 to 24 years between 1960 and 1995 were studied. From 1960 to 1995 in males of all ages and in females aged 6–14 years height, weight and BMI increased. In females aged 15–24 years, the height increased and the weight slightly increased, but the BMI gradually decreased from 21.5 in 1960 to 20.5 in 1995. Over the last 35 years adolescent and young adult women have become thinner. Dieting to be slim has become much more prevalent among young women. These findings suggest that young females in Japan have decreased their BMI by dieting in order to become slim. If this tendency persists, with regard to a close relationship between restrained eating or dieting and eating disorders, Japanese young women have a much greater risk of developing eating disorders.