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iMedicalApps and JMIR Publications have partnered to help disseminate interesting and innovative digital health research being done worldwide. Each article in this series will feature summaries of interesting studies from the study authors to help you keep up to date on the latest in digital health research. We invite you to share your thoughts on the study in the comments section.

Smartphone apps for weight-loss: quality assessment of the evidence-base for the most popular apps

1. What was the motivation behind your study?

Smartphone ownership and app use have rapidly risen over recent years. Individuals in the public have readily taken to using commercial health and fitness apps to track and improve their health behaviors and well being, as well as to lose weight. However, there has been little done to assess the quality and effectiveness of dietary weight loss apps. Further, as there are no industry standards or regulations governing the quality of commercial weight loss apps, our aim was to conduct an evaluation of popular commercial weight loss apps.

2. Describe your study.

For this study, we looked through 800 popular commercial “health and fitness” apps to find those that focused on weight management and had a facility to record food intake. The 28 apps fitting these criteria were used for five days and assessed against quality measures including: the app’s credibility, accuracy and coverage of scientific information relevant to weight management, inclusion of technology-enhanced features and its usability. We also scored apps for their inclusion of elements that could facilitate changes in an individual’s behavior, also known as behavior change techniques.

3. What were the results of the study?

From our evaluation, we found that overall the most popular commercial apps for weight loss were sub-optimal in quality, with apps lacking in their incorporation of behavior change techniques (with an average of only 6.3 of 26 techniques included). However, positively, popularity of apps was associated with quality – such that more popular apps were significantly associated with a higher total quality assessment score, greater accuracy and coverage of scientific information related to weight management, more technology-enhanced features, and greater inclusion of behavior change techniques.

4. What is the main point that readers should take away from this study?

The apps receiving the highest overall quality score were: Noom Weight Loss Coach by Noom Inc. (75 out of 100) and Calorie Counter Pro by MyNetDiary Inc. and Control My Weight by CalorieKing Wellness Solutions equal second (65 out of 100). MyFitnessPal, which ranks as the number 1 health and fitness app in the app stores, only received a score which placed it as equal 9th (54.5 out of 100) out of the 28 apps evaluated.

5. What was the most surprising finding from your study?

We know from our evaluation that most commercial dietary weight loss apps are calorie counters. When we investigated the accuracy of the energy intake calculations given by the apps by comparison with results from a “gold-standard” three-day weighed food record, we were actually surprised to find that popular weight loss dietary apps were fairly accurate. The mean difference between the apps and the gold standard was 127kJ, although there was some larger variability across different apps.

6. What are the next steps? How do you envision this work ultimately translating into clinical practice or affecting R&D?

With the limited public understanding about the best quality apps to use, our evaluation provides guidance for consumers and clinicians of the higher quality apps among the current pool of popular weight loss apps on the markets that could be selected. Our findings may also drive the development of industry standards or evaluation frameworks of weight management apps where they are currently lacking.

This Q&A was submitted by Juliana Chen, a dietitian and PhD student from the School of Molecular Bioscience and the Charles Perkins Centre for Obesity, Diabetes, and Cardiovascular Disease of the University of Sydney.