Validation of a food frequency questionnaire in preschool children.

BACKGROUND: Support for the validity of food frequency questionnaires (FFQ) in preschool children using parental report is limited.
METHODS: We obtained dietary information for 68 children age 1-3 years using three or four 24-hour recalls and a FFQ regarding the child's diet covering one year from families in Denver, CO from 1997 to 1999. FFQs were completed by the parents, and recalls were collected via interviews with the parents and alternate caregivers, where applicable. Nutrient biomarkers were measured in the plasma of 38 of the children. All nutrients were adjusted for energy intake using residuals, and log-transformed where necessary.
RESULTS: Correlations (Pearson r) between the FFQ and the average of the recalls were 0.33 for protein, 0.41 for carbohydrate, 0.39 for fat, 0.42 for vitamin C, 0.27 for alpha-tocopherol, and 0.08 for total energy intake. We found no substantial changes in these correlations after stratification by whether or not meals and snacks were provided by caregivers other than the parents. The highest correlations (Spearman r) with biological measures were 0.51 between plasma ascorbic acid and FFQ vitamin C, and 0.48 between plasma and FFQ alpha-tocopherol.
CONCLUSIONS: The FFQ shows mostly good agreements with multiple 24-hour recalls and biomarkers in preschool children. In addition, the validity of the FFQ using parental report does not appear to be compromised when there are meal providers in addition to the parents.