A comparative validation of a child food frequency questionnaire using red blood cell membrane fatty acids

There are limited validated tools available for the assessment of dietary intake in pediatric populations. This report describes a comparative validation study of selected fatty acid intakes in children assessed by food frequency questionnaire (FFQ), compared with erythrocyte membrane fatty acids. Overall, 46 overweight and 47 healthy-weight children aged 5–12 years (mean±SD, 9.1±1.3years, body mass index 20.5±4.0) were recruited; dietary fatty acid intakes assessed by parent report using a 135-item semi-quantitative FFQ, were compared with selected child erythrocyte membrane fatty acids assessed from fasting samples using gas chromatography. Spearman's rank correlation coefficients were calculated between fatty acid intake estimates (% of energy) and erythrocyte membrane concentrations (%mol/mol). Significant correlations were found between dietary and erythrocyte eicosapentanoic acid (EPA) concentration (r=0.24, P<0.05) with a statistical trend for total omega three (∑n-3) fatty acids (r=0.22, P=0.06) and linoleic acid (r=0.32, P=0.07) in the healthy-weight children only. Parental report of selected child fatty acid intakes using an FFQ can be used to provide an estimate of child intake of EPA, but further work is required to quantify this relationship for other fatty acids and in other populations.