TY  - JOUR
AU  - Klasen, Linda
AU  - Koch, Stefanie Anna Julia
AU  - Benz, Maike Elena
AU  - Conrad, Johanna
AU  - Alexy, Ute
AU  - Blaszkiewicz, Konrad
AU  - Andone, Ionut
AU  - Nöthlings, Ute
PY  - 2025
DA  - 2025/2/10
TI  - NutriDiary, a Smartphone-Based Dietary Record App: Description and Usability Evaluation
JO  - JMIR Hum Factors
SP  - e62776
VL  - 12
KW  - dietary assessment
KW  - food record
KW  - barcode scanning
KW  - app
KW  - mobile phone
AB  - Background: Repeated applications of short-term dietary assessment instruments are recommended for estimating usual dietary intake. For this purpose, NutriDiary, a smartphone app for collecting weighed dietary records (WDRs) in the German population, was developed. Objective: We aim to describe NutriDiary and evaluate its usability and acceptability. Methods: NutriDiary was developed as a WDR, allowing users to enter food items via text search, barcode scanning, or free text entry. The sample for the evaluation study included 74 participants (n=51, 69% female, aged 18‐64 years), including 27 (37.5%) experts and 47 (63.5%) laypersons (including n=22, 30%, nutrition students). Participants completed a 1-day WDR and entered a predefined sample meal (n=17 foods) the following day by using NutriDiary. An evaluation questionnaire was answered from which the system usability scale (SUS) score (0‐100) was calculated. A backward selection procedure (PROC REG in SAS; SAS Institute) was used to identify potential predictors for the SUS score (age, sex, status [expert or laypersons], and operating system [iOS or Android]). Results: The median SUS score of 75 (IQR 63‐88) indicated good usability. Age was the only characteristic identified as a potential predictor for a lower SUS score (P<.001). The median completion time for an individual WDR was 35 (IQR 19‐52) minutes. Older participants took longer to enter the data than younger ones (18‐30 y: median 1.5, IQR 1.1‐2.0 min/item vs 45‐64 y: median 1.8, IQR 1.3‐2.3 min/item). Most participants expressed a preference for NutriDiary over the traditional paper-based method. Conclusions: Good usability and acceptability make NutriDiary promising for use in epidemiological studies. 
SN  - 2292-9495
UR  - https://humanfactors.jmir.org/2025/1/e62776
UR  - https://doi.org/10.2196/62776
DO  - 10.2196/62776
ID  - info:doi/10.2196/62776
ER  -