Body image and body satisfaction play important roles in the path to dieting behavior in Japanese preadolescents: The Toyama birth cohort study.

OBJECTIVES To analyze the path to dieting behavior in Japanese preadolescents. METHODS A cross-sectional study of dieting behavior among 5,244 preadolescents (2,452 boys and 2,792 girls aged 12-13) born in Toyama prefecture. RESULTS While increasing with body mass index (BMI), the percentage of those who had tried dieting was higher in those who perceived themselves fat than in those who perceived themselves thin or average. Of those who wanted to be thinner, 16.1% of boys and 26.8% of girls had tried dieting. Path analysis in nonobese subjects (2,116 boys and 2,334 girls) showed that (1) body image was primarily based on BMI, (2) body image led to body dissatisfaction, and (3) body dissatisfaction led to dieting behavior. Pubertal changes had a significant effect on body image (path coefficient <0)for boys and body satisfaction (path coefficient >0) for girls, in addition to that on BMI. Maternal BMI had a significant effect on BMI but not on body image, body satisfaction, or dieting behavior. CONCLUSIONS Body image and body satisfaction play important roles in the path to dieting behavior in Japanese preadolescents. Pubertal changes may reinforce dieting behavior, but the mechanism may differ by sex.