Validity and test-retest reliability of a short dietary questionnaire to assess intake of saturated fat and free sugars: A preliminary study

Background: The present study aimed to conduct a preliminary investigation of the validity and reliability of a short dietary questionnaire designed to assess dietary intake of saturated fat and free sugars. Methods: Forty students at Macquarie University, aged 17-46 years, completed the Dietary Fat and free Sugar - Short Questionnaire (DFS), a full-length food frequency questionnaire (C-FFQ) and a 4-day diet diary (DD). After a mean (SD) follow-up time of 158 (10) days, 29 participants completed a second administration of the DFS. Results: Correlation coefficients comparing DFS scores with the percentage energy from saturated fat and free sugar assessed by the C-FFQ and DD ranged from 0.35 to 0.71. The intraclass correlation (0.83) was high, indicating good reliability. Conclusions: These results suggest that the DFS is a valid and reliable measure of saturated fat and free sugar intake. Because it is quick to administer and score, in the public domain, and easy to interpret, it maybe useful as a screener, simple self-check tool or for large-scale epidemiological studies.