Assessment of the eNutri personalized nutrition tool in Germany – Usability metrics and users’ experiences (Preprint)

Abstract

BACKGROUND Adequate dietary intake assessments are needed to determine the actual nutrition intake of a population. Paper-pen versions have long been used as validated dietary assessment tools, but in the age of digitalization, these tools are increasingly becoming converted into digital versions. We developed a validated Food Frequency Questionnaire (FFQ) integrated into the eNutri web application (app) to capture dietary intake tailored to a Western European population and provide dietary recommendations in a digital format. OBJECTIVE The primarily focus of this study was to evaluate the system usability and users’ feedback of the eNutri app. METHODS The app was piloted for four weeks by 106 participants from Germany divided into a Personalized Nutrition (PN) group and a control group. The groups differed according to the degree of personalization of dietary recommendations obtained. RESULTS An overall system usability score (SUS) of 78.4 (SD 12.2) was yielded, indicating an above average user experience. Mean completion time of the FFQ was 26.7 minutes (SD 10.6). Across subgroups (age, sex, screen sizes) no differences in SUS or completion time were found, indicating an equal performance for all users independent of the assigned experimental group. Participants´ feedback highlighted the need for more personalized dietary advice for control subjects. Further improvements of the eNutri app were suggested by the app users. CONCLUSIONS In total, eNutri provides a validated FFQ in a web-based graphical version, considering nutritional specificities of the German population. It was well received and supportive comments for further development of the digital diet assessment tool (e.g., more detailed dietary feedback) has been provided by the users.