Combined interventions for physical activity, sleep, and diet using smartphone apps: A scoping literature review.

BACKGROUND: The use of smartphone apps to track and manage physical activity (PA), diet, and sleep is growing rapidly. Many apps aim to change individual behavior on these three key health dimensions (PA, sleep, diet) by using various interventions. Earlier reviews have examined interventions using smartphone apps for one or two of these dimensions. However, there is lack of reviews focusing on interventions for all three of these dimensions in combination with each other. This is important since the dimensions are often inter-related, and all are required for a healthy lifestyle. OBJECTIVE: The objective of this study is to conduct a review to: (1) map out the research done using smartphone app interventions targeting all three or any two of the three dimensions (PA, sleep, and diet), (2) examine if the studies consider the inter-relationships among the dimensions, and (3) identify the personalization methods implemented by the studies. METHODS: A literature search was conducted in electronic databases and libraries related to medical and informatics literature - PubMed, ScienceDirect, PsycINFO (ProQuest, Ovid) - using relevant selected keywords. Article selection and inclusion were done by removing duplicates, analyzing titles and abstracts, and then reviewing the full text of the articles. RESULTS: In the final analysis, 14 articles were selected - 2 articles focusing on PA and sleep, 8 on PA and diet, and 4 that examine or (at least) collect data of all three dimensions (PA, sleep, and diet). No research was found that focused on sleep and diet together. Of the 14 articles, only 4 build user profiles. Further, 3 of these 4 studies deliver personalized feedback based on the user's profile, with only 1 study providing automated, personalized recommendations for behavior change. Additionally, 6 of the included studies report all positive outcomes, while for 3 studies the primary outcomes are awaited. The remaining 5 studies do not report significant changes in all outcomes. In all, only 1 study examines the relationship between two (PA and diet) dimensions. No study was found to assess the relationships among the 3 dimensions.