Validity and reproducibility of a semi-quantitative food-frequency questionnaire for estimating calcium intake in Belgian preschool children

Relative validity and reproducibility of a semi-quantitative food-frequency questionnaire (FFQ) for measuring preschool children's usual Ca intake were assessed using parents or guardians as a proxy. Estimated diet records (EDR; 3d) were used as the reference method and reproducibility was measured by repeated FFQ administrations 5 weeks apart. From 2095 preschool children (2·5–6·5 years) randomly selected in Flanders (Flemish region of Belgium), 1052 returned a FFQ and EDR. Stringent exclusion procedures reduced the sample for validity analyses to 509 children. From a separate sample of 244 p... Mehr ...