Background: Estimates of energy intake are required for an understanding of growth and disease; however, few methods of energy intake in children have been validated.
Objective: Our objective was to validate energy intake estimated by the Youth-Adolescent Food-Frequency Questionnaire (YAQ) against the criterion total energy expenditure (TEE) by doubly labeled water (DLW).
Design: Twenty-three boys and 27 girls (8.6-16.2 y of age) completed the YAQ and TEE measurements in 1 y.
Results: Energy intake by the YAQ (10. 03 +/- 3.12 MJ) and energy expenditure by DLW (9.84 +/- 1.79 MJ) were similar (P: = 0.91) with large lower (-6.30 MJ) and upper (6.67 MJ) +/-2 SD limits of agreement. When within-subject CVs of repeated measures of the DLW and YAQ methods were used, 25 of the 50 subjects were deemed to have misreported their energy intake. The discrepancy in energy intake (YAQ - TEE) was related to body weight (r = -0.25, P: = 0.077) and percentage body fat (r = -0.24, P: = 0.09) but not to age (r = -0.07, P: = 0.63) or the time between measures. From logistic regression, fatter boys were more likely to underreport energy intake than were fatter girls.
Conclusion: The YAQ provides an accurate estimation of mean energy intake for a group but not for an individual.