Smartphone Apps for Food Purchase Choices: Scoping Review of Designs, Opportunities, and Challenges.

BACKGROUND: Smartphone apps can aid consumers in making healthier and more sustainable food purchases. However, there is still a limited understanding of the different app design approaches and their impact on food purchase choices. An overview of existing food purchase choice apps and an understanding of common challenges can help speed up effective future developments. OBJECTIVE: We examined the academic literature on food purchase choice apps and provided an overview of the design characteristics, opportunities, and challenges for effective implementation. Thus, we contribute to an understanding of how technologies can effectively improve food purchase choice behavior and provide recommendations for future design efforts. METHODS: Following the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews) guidelines, we considered peer-reviewed literature on food purchase choice apps within IEEE Xplore, PubMed, Scopus, and ScienceDirect. We inductively coded and summarized design characteristics. Opportunities and challenges were addressed from both quantitative and qualitative perspectives. From the quantitative perspective, we coded and summarized outcomes of comparative evaluation trials. From the qualitative perspective, we performed a qualitative content analysis of commonly discussed opportunities and challenges. RESULTS: We retrieved 55 articles, identified 46 unique apps, and grouped them into 5 distinct app types. Each app type supports a specific purchase choice stage and shares a common functional design. Most apps support the product selection stage (selection apps; 27/46, 59%), commonly by scanning the barcode and displaying a nutritional rating. In total, 73% (8/11) of the evaluation trials reported significant findings and indicated the potential of food purchase choice apps to support behavior change. However, relatively few evaluations covered the selection app type, and these studies showed mixed results. We found a common opportunity in apps contributing to learning (knowledge gain), whereas infrequent engagement presents a common challenge. The latter was associated with perceived burden of use, trust, and performance as well as with learning. In addition, there were technical challenges in establishing comprehensive product information databases or achieving performance accuracy with advanced identification methods such as image recognition. CONCLUSIONS: Our findings suggest that designs of food purchase choice apps do not encourage repeated use or long-term adoption, compromising the effectiveness of behavior change through nudging. However, we found that smartphone apps can enhance learning, which plays an important role in behavior change. Compared with nudging as a mechanism for behavior change, this mechanism is less dependent on continued use. We argue that designs that optimize for learning within each interaction have a better chance of achieving behavior change. This review concludes with design recommendations, suggesting that food purchase choice app designers anticipate the possibility of early abandonment as part of their design process and design apps that optimize the learning experience.

From work stress to disease: A computational model.

In modern society, work stress is highly prevalent. Problematically, work stress can cause disease. To help understand the causal relationship between work stress and disease, we present a computational model of this relationship. That is, drawing from allostatic load theory, we captured the link between work stress and disease in a set of mathematical formulas. With simulation studies, we then examined our model's ability to reproduce key findings from previous empirical research. Specifically, results from Study 1 suggested that our model could accurately reproduce established findings on daily fluctuations in cortisol levels (both on the group level and the individual level). Results from Study 2 suggested that our model could accurately reproduce established findings on the relationship between work stress and cardiovascular disease. Finally, results from Study 3 yielded new predictions about the relationship between workweek configurations (i.e., how working hours are distributed over days) and the subsequent development of disease. Together, our studies suggest a new, computational approach to studying the causal link between work stress and disease. We suggest that this approach is fruitful, as it aids the development of falsifiable theory, and as it opens up new ways of generating predictions about why and when work stress is (un)healthy.

No pain, no gain? Recovery and strenuousness of physical activity.

The present study aimed to advance insight in the role of leisure time physical activity (LTPA) in the recovery process, by focusing on the strenuousness of LTPA. It was proposed that-compared with less strenuous LTPA-more strenuous LTPA would show stronger positive relationships with recovery through higher levels of mental disengagement from stressors resulting from more strenuous LTPA. This hypothesis was examined in two studies, in which participants' positive and negative affective states were included as indicators of recovery. Study 1 was a 10-day daily diary study (3 measurements daily) among 74 employees. Each day, participants reported the time they had spent on mild, moderate, and strenuous LTPA. Multilevel path analysis showed that only strenuous LTPA was related to beneficial changes in the two indicators of recovery before bedtime and in the next morning through its positive relationship with psychological detachment from work. Study 2 was an experiment with two between-participants conditions, in which-after a stress-inducing task-44 participants engaged in either (a) a 20-min moderate intensity cycling task, or (b) a 20-min high intensity cycling task. Results showed that high intensity exercise was indirectly related to higher recovery as indicated by a lower level of participants' negative affective state, through lower levels of rumination about the stress-inducing task in this condition. The results of these two studies indicate that to fully savor LTPA's beneficial effects through mental disengagement from stressors, it is best conducted with a high level of strenuousness. (PsycINFO Database Record (c) 2019 APA, all rights reserved).