Validity of a food frequency questionnaire to estimate mean nutrient intake of Italian school children

Abstract We report on the ability of a food frequency questionnaire (FFQ) to estimate the mean nutrient intake at population level for an Italian pediatric population. Three-hundred and twenty-three healthy, fourth grader school children (158 females, 165 males) were enrolled (mean age = 9.3 years, range 8.1–10.6). Data collected from the FFQ was compared with a 24-hour dietary recall that is known to yeald good estimates of group mean nutrient intake. The 24-hour dietary recall was compiled by trained personnel who interviewed the children's mothers. Nutrient intakes were calculated using the Italian National Institute for Nutrition nutrient composition data base. The FFQ was designed according to Block 's procedure. Data were expressed as nutrient densities to adjust for caloric intake. The comparison between the two methods of nutrient intake evaluation was assessed separately for males and females by Student's t-test for paired samples. Energy intake was found to be higher among both males and in females. For females, protein (−9%) and cholesterol (−11%) were found to be significantly lower with FFQ than with 24-hour dietary recall. For all other nutrients the mean difference was