Relationship between Violent Behavior and Repeated Weight-Loss Dieting among Female Adolescents in Japan

Purpose: To examine whether interpersonal violence perpetration and violence toward objects are associated with body mass index (BMI), body weight perception (BWP), and repeated weight-loss dieting in female adolescents. Methods: A cross-sectional survey using a self-report questionnaire was performed evaluating interpersonal violence perpetration, violence toward objects, the number of diets, BMI, BWP, the 12-item General Health Questionnaire (GHQ-12), victimization, substance use, and other psychosocial variables among 9,112 Japanese females aged between 12-18 years. Logistic regression analysis was conducted to analyze the contribution of BMI, BWP, and weight-control behavior to the incidence of violent behavior, while controlling for potential confounding factors. Results: The number of diets was associated with both interpersonal violence perpetration (OR = 1.18, 95% CI 1.08-1.29, p<0.001) and violence toward objects (OR = 1.34, 95% CI 1.24-1.45, p<0.001), after adjusting for age, BMI, BWP, the GHQ-12 total score, victimization, and substance use. In terms of BMI and BWP, the overweight'' BWP was associated with violence toward objects (OR = 1.29, 95% CI 1.07-1.54, p<0.05). On the other hand, the Underweight'' and Slightly underweight'' BMI were related to violence toward objects [(OR = 1.28, 95% CI 1.01-1.62, p<0.05) and (OR = 1.27, 95% CI 1.07-1.51, p<0.05), respectively]. The Underweight'' BWP was related to interpersonal violence perpetration (OR = 2.30, 95% CI 1.38-3.84, p<0.05). Conclusions: The cumulative number of diets is associated with violent behavior in female adolescents. In addition, underweight BMI and extreme BWP are associated with violent behavior.