Reprodutibilidade e validade de um questionário de frequência alimentar em adultos da cidade de Porto Alegre/RS

Abstract

To assess the reproducibility and validity of a food frequency questionnaire in adults living in south of Brazil. The food frequency questionnaire was administered twice in 83 participants, ages 20 to 69. The reproducibility was tested with Spearman correlations and intra-class correlation coeficients. To validity, average nutrient intake from the three 24h dietary recalls were compared to average intakes from each FFQs (FFQ1 and FFQ2) by calculating Pearson correlation coefficients and adjusting for energy intake and within person variation. The nutrients were categorized into quartiles. The average intake was higher for deal of nutrients in the FFQ1 and FFQ2, when it was compared with average intake from the three IR24h. The average correlation coefficients intra-class was 0,63, while the average, considering, Spearman correlation was 0,62. To the validity, our founds was 0,41, the average of Pearson correlation to a FFQ1 and 0,46 to FFQ2. The average classification percentage in the same quartile for the