Associations between the Youth/Adolescent Questionnaire, the Youth/Adolescent Activity Questionnaire, and body mass index z score in low-income inner-city fourth through sixth grade children

Background: Diet and physical activity are important factors in the etiology, prevention, and treatment of chronic diseases such as obesity and its associated comorbidities. Accurate measures of diet and activity are critical in understanding how these lifestyle and behavioral factors covary to affect health status. Objective: The purpose of this study was to investigate the relation between body mass index (BMI) z score and self-report measures of diet and activity, the Youth/Adolescent Questionnaire (YAQ) and the Youth/Adolescent Activity Questionnaire (YAAQ), respectively. Design: Participants were 1092 students in grades 4 through 6 from 10 schools in a US city in the middle Atlantic region with >= 50% of students eligible for free or reduced-price meals. Students were assessed at baseline and again after 2 y. The relation between self-reported energy intake (YAQ) and activity (physical and sedentary) (YAAQ) and BMI z score was explored from both a cross-sectional and longitudinal perspective. Results: The YAQ (energy intake) and YAAQ (physical and sedentary activity) did not relate to BMI z score in the expected directions from either a cross-sectional or longitudinal perspective. Conclusion: In this large, racially diverse sample, the YAQ and the YAAQ were not significantly associated with BMI z score or changes in BMI z score.