Applied nutritional investigationValidation of an Australian electronic food frequency questionnaire to measure polyunsaturated fatty acid intake
Introduction
Since the discovery of a low incidence of atherosclerotic heart disease among Eskimo populations [1], there has been a growing interest in long-chain omega-3 polyunsaturated fatty acids (LC n-3 PUFA) and their role in health and disease. These LC n-3 PUFA are primarily found in fish/seafood but also in meat and eggs [2], and there are several assessments of dietary intakes. A weighed food record (FR) is often used as a reference method [3], while a food frequency questionnaire (FFQ) captures the consumption frequency and portion size for each food, during a specified reference time [4]. The questionnaire is a measure of long-term food intake, is relatively inexpensive, is substantially less time-consuming than other methods, and can be self-administered [5].
With an increasing demand for time-saving and cost-efficient tools to measure dietary intake, an FFQ in electronic format shows great potential. Several studies have implemented the use of a computerized FFQ in dietary studies [6], [7]. Administering a FFQ in this form makes efficient use of time, and manual calculation of intakes is not required [8]. Skip patterns can also be incorporated into the questionnaire to avoid non-applicable questions (eg, meat questions for vegetarians) [6], [8], and the computerized FFQ can overcome problems of incomplete answers and/or missed pages [9].
A LC n-3 PUFA FFQ was validated by Sullivan et al. [10], [11], but this valid tool only focussed on LC n-3 PUFA and relied on manual calculation of LC n-3 PUFA intakes. To overcome these limitations, the existing LC n-3 PUFA FFQ was expanded to include foods containing linoleic acid (LA), arachidonic acid (AA), and alpha-linolenic acid (ALA) and subsequently became the PUFA FFQ. This new PUFA FFQ was adapted for electronic use, which automatically calculated PUFA intakes.
The aims were to validate the new electronic PUFA FFQ using the method of triads, test its reproducibility, and evaluate the ease of its use.
Section snippets
Ethics, subject recruitment, and clinic visits
This study was conducted according to the guidelines laid down in the Declaration of Helsinki, and all procedures involving human subjects were approved by the University of Wollongong Human Research Ethics Committee. Written informed consent was obtained from all volunteers.
Adults were recruited from medical practices, recreation centers, and clubs in the Illawarra region, New South Wales, Australia. For inclusion in the study, subjects were required to be generally healthy and to have
Results
Forty-eight study subjects (23 male and 25 female) were recruited for the study and 7 subjects (3 male and 4 female) were then excluded from analysis due to underreporting in the FR [17]. There was a wide representation of ages in the cohort; two subjects were vegetarians and 9 subjects consumed fish oil regularly. Subject characteristics are presented in Table 1.
Discussion
This study showed that the self-administered electronic PUFA FFQ provided a useful estimate of PUFA intakes in a healthy adult population. By using the method of triads, PUFA intakes could be estimated using both dietary methods and biomarkers. The PUFA FFQ adequately estimated intakes for EPA, DHA, total LC omega-3 PUFA, LA, and total PUFA, which were comparable with results from the 3-d weighed FR. EPA, DHA, and total LC omega-3 PUFA were well represented in both erythrocytes and plasma
Conclusion
In conclusion, the electronic PUFA FFQ is a valid tool to assess PUFA intakes in a healthy adult population. Further research into the use of this questionnaire is warranted in different populations.
Acknowledgments
The authors would like to thank Sheena McGhee for assistance with the clinic visits, Amanda Lane for fatty acid analysis training, Widya Wijaya for writing the web-based electronic PUFA questionnaire, Serina Faraji for training in the Foodworks software, and the study subjects who were involved in the study.
This work was supported by the Metabolic Research Centre, University of Wollongong.
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