title: Popular Mobile Phone Apps for Diet and Weight Loss: A Content Analysis.
abstract: BACKGROUND
  A review of the literature has revealed that the rates of overweight and obesity have been increasing in Australia over the last two decades and that wellness mobile phone apps play a significant role in monitoring and managing individuals' weight. Although mobile phone app markets (iTunes and Google Play) list thousands of mobile phone health apps, it is not always clear whether those apps are supported by credible sources. Likewise, despite the prevailing use of mobile phone apps to aid with weight management, the usability features of these apps are not well characterized.
  
  
  OBJECTIVE
  The research explored how usability taxonomy could inform the popularity of downloaded, socially focused wellness mobile phone apps, in particular weight loss and diet apps. The aim of the study was to investigate the Australian mobile phone app stores (iTunes and Google Play) in order to examine the usability features of the most popular (ie, most downloaded) wellness apps.
  
  
  METHODS
  The design of this study comprises 3 main stages: stage 1, identifying apps; stage 2, development of weight loss and diet evaluation framework; and stage 3, application of the evaluation framework. Each stage includes specific data collection, analysis tools, and techniques.
  
  
  RESULTS
  The study has resulted in the development of a justified evaluation framework for weight loss and diet mobile phone apps. Applying the evaluation framework to the identified apps has shown that the most downloaded iTunes and Google Play apps are not necessarily the most usable or effective. In addition, the research found that search algorithms for iTunes and Google Play are biased toward apps' titles and keywords that do not accurately define the real functionality of the app. Moreover, the study has also analyzed the apps' user reviews, which served as justification for the developed evaluation framework.
  
  
  CONCLUSIONS
  The analysis has shown that ease of use, reminder, bar code scanning, motivation, usable for all, and synchronization are significant attributes that should be included in weight loss and diet mobile phone apps and ultimately in potential weight loss and diet evaluation frameworks.
authors.affiliation: School of Computing and Information Systems, Faculty of Science, Engineering and Technology, University of Tasmania, Hobart, Australia. sarahbzaidan@gmail.com.
authors.forename: Sarah
authors.identifier: http://orcid.org/0000-0002-5018-8297
authors.initials: S
authors.lastname: Zaidan
authors.forename: Erin
authors.identifier: http://orcid.org/0000-0001-6211-7747
authors.initials: E
authors.lastname: Roehrer
keywords: applications; diet; monitoring; obesity; weight loss