Reliability and validity of assessing energy and nutrient intake with the Vienna food record: a cross-over randomised study

BACKGROUND: The Vienna Food Record was developed as a simple paper-based pre-coded food record for use in Austrian adults, which can be completed over a flexible period of time. The present study aimed at evaluating test-retest reliability of the Vienna Food Record and its concurrent validity against a weighed food record. METHODS: A randomised cross-over study served to compare outcomes of the Vienna Food Record with those of the weighed food record. The Vienna Food Record was completed for a second time, in order to assess test-retest reliability. Three assessment phases were interrupted by two-week wash-out phases. Sixty-seven free living Austrians aged 18-64 years, without (self-) diagnosed food allergies or intolerances, not at any medication, and not nutrition experts, were randomly assigned to one of two study arms. After drop-outs and exclusion of under-reporters, data of 35 participants has been analysed. Paired t-tests were performed for comparisons, regarding test-retest reliability and criterion validity, where mean differences were calculated as effect sizes. Consistency between repeated assessments with the Vienna Food Record was expressed by intra-class-correlation coefficients (ICC), while Pearson's r was used for agreement regarding validity. Bland-Altman Plots with 95% limits of agreement were created for energy and macronutrients. Validity metrics for macronutrients were analysed additionally separated by gender, taking an adjustment of energy intake into account. Total energy intakes as well as intakes of macro- and selected micronutrients, expressed as daily means, were defined as 34 primary outcomes. RESULTS: ICCs for energy and intake of preselected nutrients, expressing the consistency of the Vienna Food Record, ranged from not significant to 0.95. Pearson's correlation coefficients, expressing the agreement of the Vienna Food Record with the weighed food record ranged from not significant to 0.80. CONCLUSIONS: This study demonstrates acceptable reliability and validity of the Vienna Food Record as an instrument for the assessment of energy and nutrient intake, comparable to the results of similar studies.