Adaptation and validation of an FFQ for 6-10-year-old children.

ABSTRACT

OBJECTIVE: To adapt and test the relative validity of an instrument measuring the usual food intake of 6-10-year-old children. DESIGN: An FFQ encompassing the preceding 6 months was adapted and compared with the average of three 24 h dietary recalls. SETTING: Private and public schools in Porto Alegre, capital city of Rio Grande do Sul, the southernmost state in Brazil, with 1·5 million inhabitants. SUBJECTS: Children aged 6-10 years attending grades 1-4 in private and public schools in Porto Alegre. RESULTS: Ninety-one children were studied. The FFQ overestimated all nutrients. Correlations with the values obtained by 24 h dietary recalls were mostly above 0·50. The deattenuated correlations increased for all nutrients. The κ coefficients for the adjusted nutrients varied from 0·12 (weak) to 0·34 (reasonable). Graphically, the FFQ was shown to underestimate some of the parameters and to overestimate others, with a wide CI for all nutrients. CONCLUSIONS: The FFQ does not have the required relative validity to classify the intake levels of schoolchildren, and further investigation is required to understand the sources of error.