The aim of this study was to assess the validity of the third version of the Previous Day Food Questionnaire (PDFQ-3) for schoolchildren. PDFQ-3 is a structured instrument with 6 meals and 21 foods. The study included 164 students aged 6 to 11 years in a public school with a full-day school schedule in 2007. Validity was assessed by comparing food items selected on the questionnaire and direct observations of foods eaten in three school meals on the previous day (mid-morning snack, lunch, and mid-afternoon snack). Multivariate logistic regression analysis was used to evaluate the discordance between answers from the questionnaire versus those from observations. Results indicated high sensitivity and specificity for the majority of the food items. Mean values for sensitivity and specificity were 70.5% and 87.1%, respectively, for 12 food items in three combined school meals. Schoolchildren aged 6 to 8 years showed higher discordance between PDFQ-3 and observations, compared to 9-to-11-year-olds. Based on the findings, the PDFQ-3 can generate valid data for the evaluation of previous day food consumption in groups of schoolchildren.
Food Consumption; Questionnaires; Child
