Weight Loss Following Use of a Smartphone Food Photo Feature: Retrospective Cohort Study.

BACKGROUND: Tracking of dietary intake is key to enhancing weight loss. Mobile apps may be useful for tracking food intake and can provide feedback about calories and nutritional value. Recent technological developments have enabled image recognition to identify foods and track food intake. OBJECTIVE: We aimed to determine the effectiveness of using photography as a feature of a smartphone weight loss app to track food intake in adults who were overweight or obese. METHODS: We analyzed data from individuals (age, 18-65 years; body mass index≥25 kg/m2; ≥4 days of logged food intake; and ≥2 weigh-ins) who used a mobile-based weight loss app. In a retrospective study, we compared those who used the photo feature (n=9871) and those who did not use the feature (n=113,916). Linear regression analyses were used to assess use of the photo feature in relation to percent weight loss. RESULTS: Weight loss was greater in the group using the photo feature (Δ=0.14%; 95% CI 0.06-0.22; P<.001). The photo feature group used the weight loss app for a longer duration (+3.5 days; 95% CI 2.61-4.37; P<.001) and logged their food intake on more days (+6.1 days; 95% CI 5.40-6.77; P<.001) than the nonusers. Mediation analysis showed that the weight loss effect was absent when controlling for either duration or number of logged days in the program. CONCLUSIONS: This study was the first to examine the effect of a food photo feature to track food intake on weight loss in a free-living setting. Use of photo recognition was associated with greater weight loss, which was mediated by the duration of app use and number of logged days in the program.

Reciprocal cellular cross-talk within the tumor microenvironment promotes oncolytic virus activity.

Tumors are complex ecosystems composed of networks of interacting 'normal' and malignant cells. It is well recognized that cytokine-mediated cross-talk between normal stromal cells, including cancer-associated fibroblasts (CAFs), vascular endothelial cells, immune cells, and cancer cells, influences all aspects of tumor biology. Here we demonstrate that the cross-talk between CAFs and cancer cells leads to enhanced growth of oncolytic virus (OV)-based therapeutics. Transforming growth factor-ß (TGF-ß) produced by tumor cells reprogrammed CAFs, dampened their steady-state level of antiviral transcripts and rendered them sensitive to virus infection. In turn, CAFs produced high levels of fibroblast growth factor 2 (FGF2), initiating a signaling cascade in cancer cells that reduced retinoic acid-inducible gene I (RIG-I) expression and impeded the ability of malignant cells to detect and respond to virus. In xenografts derived from individuals with pancreatic cancer, the expression of FGF2 correlated with the susceptibility of the cancer cells to OV infection, and local application of FGF2 to resistant tumor samples sensitized them to virotherapy both in vitro and in vivo. An OV engineered to express FGF2 was safe in tumor-bearing mice, showed improved therapeutic efficacy compared to parental virus and merits consideration for clinical testing.