A Facebook-Delivered Weight Loss Intervention Using Open Enrollment: Randomized Pilot Feasibility Trial

Area of Science:

• Behavioral Science
• Digital Health
• Obesity Research

Background:

• Traditional behavioral weight loss programs face challenges with declining participant engagement over time.
• Web-based communities offer fluid membership and potentially higher engagement, which could enhance weight loss interventions.

Purpose of the Study:

• To assess the feasibility and acceptability of a continuously enrolling Facebook-delivered weight loss intervention.
• To compare open enrollment with a traditional closed enrollment model in a pilot randomized trial.

Main Methods:

• A pilot randomized trial compared open versus closed enrollment in a Facebook weight loss group for adults with BMI 27-45 kg/m².
• Feasibility outcomes included retention, engagement, and diet tracking adherence. Exploratory outcomes assessed weight loss and the relationship between engagement volume and weight loss.

Main Results:

• Open enrollment enrolled 54 additional participants, creating a larger group (94 total) with slightly lower retention (88%) than closed enrollment (98%).
• Engagement and diet tracking adherence did not differ significantly between groups. Participants favored community but desired more individualized feedback.
• Weight loss of ≥5% was achieved by 30% in the open group vs. 18% in the closed group. Higher engagement volume in the open group correlated with greater weekly weight loss.

Conclusions:

• Open enrollment is a feasible and acceptable model for Facebook weight loss interventions, comparable to closed enrollment.
• Greater overall engagement in larger, open-enrollment groups is associated with improved weight loss outcomes.
• Future research should investigate the efficacy of open enrollment in a larger, powered trial.