Validity and Reliability of a Quantitative Food Frequency Questionnaire Measuring n-3 Fatty Acid Intakes in Cardiac Patients in the Midwest: A Validation Pilot Study

Paula K. Ritter-Gooder, Nancy M. Lewis, Kimberly B. Heidal, Kent M. Eskridge

Research output: Contribution to journalArticle

14 Scopus citations


The purpose of this pilot study was to test the validity and reliability of a quantitative n-3 fatty acid food frequency questionnaire (FFQ) for later use with larger groups of individuals. A convenience sample of heart patients provided dietary data via three 24-hour food recalls and FFQs. Participants were women (n=17) and men (n=11), 43 to 77 years of age. The association of mean daily intake of n-3 fatty acids obtained using food recalls and the FFQ was assessed by Pearson correlation. The reliability of the FFQ was assessed using coefficient α. Correlation of n-3 fatty acid intake using the food recalls and the FFQ was r=0.42 (P<0.05). The coefficient α for the test-retest of the FFQ was .83. The top two foods, walnuts and flaxseed, contributed 58% of the n-3 fatty acid intake, and the third food, salmon, contributed 5%. This quantitative n-3 FFQ is a valid instrument for use in place of food recalls for estimating n-3 fatty acid intakes in heart patients and is a reliable instrument to estimate n-3 fatty acid intakes from plant, animal, and seafood sources. The FFQ should be tested in a larger population. Registered dietitians can use this FFQ to screen for intakes, educate patients on food sources, and measure change in intakes after nutrition intervention.

Original languageEnglish (US)
Pages (from-to)1251-1255
Number of pages5
JournalJournal of the American Dietetic Association
Issue number8
Publication statusPublished - Aug 1 2006


ASJC Scopus subject areas

  • Food Science
  • Nutrition and Dietetics

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