SAT-710 Early Engagement in a Shared Food Photography Log In a Smartphone App-Based Lifestyle Intervention Predicts Successful Weight Loss Months Later

Abstract Disclosure: C. Deutsch: None. B. Sheridan: None. H. Zhao: None. K.J. Williams: None. C. Vaz: None. Abstract: We previously reported that a smartphone app-based lifestyle intervention in overweight or obese participants produced statistically significant weight loss in kg at 6 months over standard-of-care in a randomized controlled clinical trial (RCT; prespecified primary outcome, ClinicalTrials.gov NCT02742662) (1). The intervention included a shared food photography log through the smartphone app where participants would post photos of their meals, snacks, and beverages for other participants and the study coach to see. Participants were also able to include descriptive information, such as type of meal (breakfast, lunch, dinner, snack) and food (fruit, vegetables, meat, pasta), as well as portion sizes (estimated by participants). The food photography log allowed participants and the study coach to share real-time messages of support by “liking”, commenting, and posting emoticons on the shared photos. We now sought to determine if individual participation in the shared food photography log could predict who would successfully lose weight by the end of the 6-month RCT. Methods of the RCT follow those previously published; n=13 in the intervention group (1). Participant food photo frequency counts included each unique photo posted per participant per week during the trial period. Average food photo frequency counts from week 1 to week 8 were compared for progressive changes in food photo posting patterns and were evaluated for correlation with participant's change in weight (%) at 6 months. Results: Food photo counts at week 1 strongly and negatively correlated with % weight change at the end of the 6-month intervention (Spearman correlation coefficient =-0.71, P =0.007). Overall, for each 1-count increase in average weekly food photo posts by a study participant, there was a corresponding additional -1% change in weight at the end of the 6-month RCT (-1% ± 0.11%, mean ± SE, P<0.0001). Conclusion: Active engagement in a shared food photography log early in the intervention was associated with clinically meaningful and statistically significant weight loss at 6 months. Our findings could help modify the existing coaching intervention for participants with a low number of food photos posted in the first week. Reference:1.Anonymous (2021). A randomized controlled trial of an innovative, user-friendly, interactive smartphone app-based lifestyle intervention for weight loss. Obes Sci Pract. 7(5), 555–568. https://doi.org/10.1002/osp4.503 Presentation: Saturday, July 12, 2025