This study included 25 761 Japanese boys and girls 6 to 15 y old. Energy intake was assessed using a self-administered diet history questionnaire developed for Japanese children and adolescents. Estimated energy requirement was calculated from self-reported body weight with the use of equations from the Food and Agriculture Organization (FAO)/World Health Organization (WHO)/United Nations University (UNU) Expert Consultation Report on Human Energy Requirements. Under-reporters, acceptable reporters, and over-reporters of energy intake were identified based on the ratio of energy intake to estimated energy requirement (<0.76, 0.76 to 1.24, and >1.24, respectively). The risk of being an under- or over-reporter of energy intake compared with being an acceptable reporter was analyzed using logistic regression.
The percentages of under-, acceptable, and over-reporters of energy intake were 31.6%, 53.2%, and 15.2%, respectively. Under-reporting was associated with female sex, older age, overweight and obesity, low parental education, and completion of the dietary questionnaire without the cooperation of parent(s)/caregiver(s). Over-reporting was associated with younger age, normal weight, low parental education, and completion of the dietary questionnaire by the child/adolescent alone (compared with completion by the child/adolescent and parent[s]/caregiver[s]).
Although under- and over-reporting of energy intake were common and differential in this study of Japanese children and adolescents, the cooperation of parent(s)/caregiver(s) in answering the dietary questionnaire seemed to improve the quality of dietary intake data.