Accepted for/Published in: JMIR mHealth and uHealth
Date Submitted: Dec 9, 2017
Open Peer Review Period: Dec 11, 2017 - Mar 15, 2018
Date Accepted: Apr 10, 2019
(closed for review but you can still tweet)
A Focused Review of Smartphone Diet-tracking Applications: Usability, Functionality, Coherence with Behavior Change Theory, and Accuracy of Nutrient Tracking
ABSTRACT
Background:
Smartphone diet-tracking applications may help individuals lose weight, manage chronic conditions, and understand dietary patterns, however, the ease of use and capabilities of these apps have not been well studied.
Objective:
The aim of this study was to review the usability of current iOS and Android diet-tracking apps, the degree to which app features align with behavior change constructs, and to assess variations between apps in nutrient coding.
Methods:
The top seven diet-tracking apps were identified from the iOS iTunes and Android Play online stores, downloaded and used over a 2-week period. Each app was independently scored using the System of Usability Scale (SUS), and features were compared to the domains in an integrated behavior change theory framework: the Theoretical Domains Framework (TDF). A 3-day food diary was completed using each app to evaluate their differences in nutrient data against the USDA reference.
Results:
Of the apps that were reviewed, LifeSum scored the highest average SUS score of 89.2, while MyDietCoach scored the lowest of 46.7. There were some variations in features noted between Android and iOS versions of the same apps, mainly for MyDietCoach, which affected SUS scoring. App features varied considerably, yet all of the apps had features consistent with Beliefs about Capabilities, and thus have the potential to promote self-efficacy by helping individuals track their diet and progress towards goals. None of the apps allowed for tracking of emotional factors that may be associated with diet patterns. The presence of behavior change domain features tended to be weakly correlated with greater usability (R2 ranging from 0 to 0.396). The exception to this was features related to the Reinforcement domain, which were correlated with less usability. Comparing the apps to the USDA reference for a 3-day diet, the average differences was 1.4 % for calories, 1.0 % for carbohydrates, 10.4% for protein, and -6.5% for fat.
Conclusions:
Diet tracking apps score well in usability, utilize a variety of behavior change constructs, and accurately code calories and carbohydrates, allowing them to play a potential role in dietary intervention studies.
Citation
Per the author's request the PDF is not available.
Copyright
© The authors. All rights reserved. This is a privileged document currently under peer-review/community review (or an accepted/rejected manuscript). Authors have provided JMIR Publications with an exclusive license to publish this preprint on it's website for review and ahead-of-print citation purposes only. While the final peer-reviewed paper may be licensed under a cc-by license on publication, at this stage authors and publisher expressively prohibit redistribution of this draft paper other than for review purposes.