Supplementary Material for: Psychometric Evaluation of the German Version of the Dietary Fat and Free Sugar-Short Questionnaire

Background: The Dietary Fat and Free Sugar-Short Questionnaire (DFS) is a cost- and timeefficient self-report screening instrument to estimate dietary intake of saturated fat and free sugar. To date, only the English version has been psychometrically evaluated. We assessed the psychometric characteristics of the German version of the DFS in individuals with normal weight, overweight, and obesity. Method: Sixty-five adult participants completed a German translation of the DFS and a validated food frequency questionnaire (FFQ). We correlated participants’ percentage of energy intake from saturated fat and free sugar from the FFQ with the DFS scores. To establish test-retest reliability, participants completed the DFS a second time. To investigate convergent validity, we correlated participants’ DFS scores with self-reported eating behavior and sensitivity to reward. Results: DFS scores correlated with percentage of energy from free sugar (rs = 0.443) and saturated fatty acids (rs = 0.258) but not with non-target nutrients. The correlation between DFS scores and percentage energy from free sugar was not moderated by body mass index (BMI), whereas the correlation with percentage energy from saturated fat slightly decreased with BMI. Intra-class correlation as an indicator of test-retest reliability was 0.801. DFS scores correlated significantly with restraint of eating behavior (rs = –0.380) and feelings of hunger (rs = 0.275). Correlations of the DFS score with disinhibited eating and sensitivity to rewards failed to be significant. Conclusion: Our data indicate that the German version of the DFS might be a psychometrically sound self-report instrument to estimate saturated fat and free sugar intake of German adults.