Using an API to Commercialize an Evidence-Based Weight Loss Intervention

This study will test the effectiveness of a mobile application that uses an Application Program Interface (API) to distribute evidence-based weight loss interventions. Half of the participants will receive this API-based application, and the other half of the participants will use a non API-based application.

The purpose of this study is to test a weight loss app that uses an API to disseminate an evidence-based weight loss intervention. The investigators hypothesize that, over the course of 12 months, participants using the Leaner app will have lost more weight than those in the attention control group. Participants (n=206) will be randomly assigned to use either the intervention app (intervention arm; n=103) or a weight loss app of their choosing (attention control arm; n=103) for 12 months. Assessments will take place at baseline, and 3, 6, and 12 months. Statistical analysis: A linear mixed modeling approach will be used to test the hypothesis. Observed weight vs. time plots will be analyzed for all participants to discern general trends in weight change. The model will include an intervention effect, a time effect, an intervention by time interaction, and a random intercept. In exploratory analysis, investigators will examine weight change across subgroups of interest; investigators will add the subgroup variable and its interaction with the intervention indicator to the primary model. All analyses will be evaluated at the 0.05 significance level.

Participants will not know which arm they have been randomized to. Additionally, the investigators will be blinded to participant assignment. Randomization will be completed by the program manager.

Mobile application that uses API technology to deliver evidence-based weight loss intervention. Includes syncing with wearable fitness tracker and scale

Mobile application that does not use API technology to deliver evidence-based weight loss intervention. Includes syncing with wearable fitness tracker and scale.

fitness tracker to monitor physical activity and sleep patterns that is connected to transfer data to app

Paffenbarger survey to capture physical activity patterns. Assesses self-report leisure time physical activity and weekly kilocalorie expenditure.

Using a blood pressure cuff, measured three times at 1-minute intervals after 5 minutes of quiet sitting. Average of final two measurements is used.

finger stick blood samples will be collected, following an overnight fast, to analyze fasting lipid profile. Samples will be analyzed using the Cholestech LDX

finger stick blood samples will be collected, following an overnight fast, to analyze plasma glucose. Samples will be analyzed using the Cholestech LDX

finger stick blood samples will be collected, following an overnight fast, to analyze high sensitivity c-reactive protein. Samples will be analyzed using the Cholestech LDX

Using technology on smart phones, we will monitor participants' app usage throughout the course of the study.

Inclusion Criteria: informed consent between 21-65 years old BMI between 25-40 kg/m2 ownership and use of an Android smartphone during past 6 months with no plans to change phone/service during study consent for research team to monitor app utilization Exclusion Criteria: use of weight loss medication prior or planned bariatric surgery psychiatric hospitalization in past 12 months pregnancy, nursing, or planned pregnancy during the study history of cardiovascular disease (CVD) event self-reported history of an eating disorder use of medication for diabetes mellitus mobility restrictions for which exercise is contraindicated history of a condition (e.g., lithium, steroids, anti-psychotics) that would affect weight measurement, for which weight loss is contraindicated current participation in another weight treatment study and/or recent weight loss >10% investigator discretion for safety reasons