User-Centered Design of a Weight Loss Mobile App

Obesity, the excessive accumulation of body fat, increases risk for chronic disease and affects 34% of U.S. adults (10). Lifestyle interventions are effective but heavily rely on calorie tracking, while adherence to this behavioral strategy is low (6). An alternative to calorie tracking is to simply track instances of overeating. In a pilot trial, obese individuals used Habit app, a mobile app that assists users in tracking overeating episodes. Users were asked to identify, record, and reflect on dietary slips, or deviations from the recommended diet. Following 6 months of use, in a focus group session, 20 participants were asked how they felt about the app’s slip tracking feature in terms of their ability to identify slips and their opinions about tracking slips. Thematic qualitative analyses were used to analyze the user’s reflections. Findings revealed that 45% of users found it difficult to know what to count as a slip, only 33.3% of users believed they tracked an accurate number of slips, and 52.6% of users found the reflective questions following tracking a slip insightful to their behavioral patterns, while others found these questions laborious or overwhelming. Users who found it easier to identify slips had a clear understanding of the dietary intervention they were provided with, indicating that having difficulty defining slips was likely a result of poor engagement with the dietary intervention. To mitigate these challenges, potential solutions aim to increase retention of the dietary intervention and personalize the slip tracker to users’ diverse experiences and emotional states.