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.

背景：膳食脂肪与游离糖简短问卷（Dietary Fat and Free Sugar-Short Questionnaire, DFS）是一种兼具成本效益与时间效率的自评筛查工具，用于估算饱和脂肪与游离糖的膳食摄入情况。截至目前，仅针对该问卷的英文版本开展过心理测量学评估。本研究针对体重正常、超重及肥胖人群，评估了DFS德文版本的心理测量学特征。
方法：65名成年受试者完成了DFS的德文翻译版本与经过验证的食物频率问卷（Food Frequency Questionnaire, FFQ）。我们将受试者通过FFQ获取的饱和脂肪与游离糖能量摄入占比，与DFS得分进行相关性分析。为建立重测信度，受试者再次完成了DFS测评。为探究聚合效度，我们将受试者的DFS得分与自评进食行为及奖赏敏感性进行相关性分析。
结果：DFS得分与游离糖能量占比（rs = 0.443）及饱和脂肪酸能量占比（rs = 0.258）呈显著相关，但与非目标营养素无相关性。DFS得分与游离糖能量占比的相关性未受体质量指数（Body Mass Index, BMI）的调节，而其与饱和脂肪能量占比的相关性则随BMI升高略有减弱。作为重测信度指标的组内相关系数为0.801。DFS得分与进食约束行为（rs = –0.380）及饥饿感（rs = 0.275）呈显著相关。DFS得分与去抑制性进食及奖赏敏感性的相关性未达到显著水平。
结论：本研究数据表明，DFS德文版本或可作为一项心理测量学性能优良的自评工具，用于估算德国成年人群的饱和脂肪与游离糖摄入情况。