Validation of self-reported energy intake by a self-administered diet history questionnaire using the doubly labeled water method in 140 Japanese adults

Objective: To validate reported energy intake (rEI) with a self-administered diet history questionnaire (DHQ) against total energy expenditure (TEE) by the doubly labeled water (DLW) method. Subjects: A total of 140 healthy Japanese adults (67 men and 73 women) aged 20-59 years living in four areas in Japan. Methods: Energy intake was assessed twice with DHQ over a 1-month period before and after TEE measurement (rEI(DHQ1) and rEI(DHQ2,) respectively). TEE was measured by DLW during 2 weeks (TEEDLW). Results: Mean rEI(DHQ1) was lower than those of TEEDLW by 1.9 +/- 2.4 MJ/day (16.4%, P<0.001) for men and 0.6 +/- 1.9 MJ/day (6.0%, P<0.01) for women. In men and women together, 62 subjects (44%) were defined as underreporters (rEI(DHQ1)/TEEDLW<0.84), 58 (41%) as acceptable reporters (0.84-1.16) and 20 (14%) as over-reporters (>1.16). Person correlation coefficient was 0.34 for men and 0.22 for women. After adjustment for the dietary and non-dietary factors related to rEI(DHQ1)/TEEDLW, the correlation coefficient improved to 0.42 and 0.37, respectively. Conclusion: The energy intake assessed with DHQ correlated low to modestly with TEE measured by DLW. In addition, DHQ underestimated energy intake at a group level. Caution is needed when energy intake was evaluated by DHQ at both individual and group levels.