VALIDITY OF A BRAZILIAN FOOD FREQUENCY QUESTIONNAIRE AGAINST DIETARY RECALLS AND ESTIMATED ENERGY-INTAKE

Food frequency questionnaires are commonly used to obtain dietary info rmation in epidemiological studies, but validity studies have primaril y been performed in western countries situated in the Northern Hemisph ere. A food frequency questionnaire for the Brazilian diet was develop ed based on a previous survey and expert decision. This questionnaire was compared with four 24-hour recalls among faculty and support staff at the University of Rio de Janeiro, Brazil; and both methods were va lidated against estimated daily energy requirement. Results of the foo d frequency questionnaire and the 24-hour recalls were correlated to a similar degree as in studies of other populations. The correlation co efficients varied from 0.55 for calcium to 0.18 for vitamin A, with al l but vitamin A being highly significant. The ratio of energy intake t o estimated basal metabolism among men was 1.37 for the 24-hour recall and 1.31 for the food frequency; among women the ratio was 1.15 for t he 24-hour recall and 1.24 for the food frequency. Women with high pre dicted energy expenditure often underestimated intake, with a greater discrepancy on the 24-hour recall than the food frequency. (C) 1998 El sevier Science Inc.