@Article{info:doi/10.2196/62776,
author="Klasen, Linda
and Koch, Stefanie Anna Julia
and Benz, Maike Elena
and Conrad, Johanna
and Alexy, Ute
and Blaszkiewicz, Konrad
and Andone, Ionut
and N{\"o}thlings, Ute",
title="NutriDiary, a Smartphone-Based Dietary Record App: Description and Usability Evaluation",
journal="JMIR Hum Factors",
year="2025",
month="Feb",
day="10",
volume="12",
pages="e62776",
keywords="dietary assessment; food record; barcode scanning; app; mobile phone",
abstract="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. ",
issn="2292-9495",
doi="10.2196/62776",
url="https://humanfactors.jmir.org/2025/1/e62776",
url="https://doi.org/10.2196/62776"
}