The validity of a food use questionnaire in assessing the nutrient intake of physically active young men

The validity of a self-administered food use questionnaire, comprising 122 questions on food items or dishes and designed especially to assess the intake of micronutrients, was evaluated using a 7-day food record (7DR) as a reference method. The subjects kept the food record after they filled in the questionnaire. Eighty-four male athletes participated in this study. The nutrient intake from the food use questionnaires was calculated in two ways: (i) in questionnaire 1 (FUQ-1), the portion size reported by the subjects was used, and (ii) in questionnaire 2 (FUQ-2), a 'typical' portion size was used regardless of the subject's report. In FUQ-1, the reported nutrient intake tended to be overestimated in comparison to the 7DR, whereas in FUQ-2 comparable results on a group level for all nutrients, except for proteins and fats, were obtained. The percentage of subjects similarly classified into tertiles (7DR vs. FUQ-1 or FUQ-2) varied between 37 and 54 per cent. The results show that the food use questionnaire agreed well with the food record on a group level, if a typical portion size was used. However, the agreement on an individual level was not quite as good.