Online Lifestyle Support for Adolescents Undergoing Metabolic and Bariatric Surgery: Pilot Prospective Cohort Study

Abstract Background Metabolic and bariatric surgery (MBS) is a safe and effective treatment for adolescents with severe obesity, yet no standardized lifestyle interventions exist to support sustained behavior change after MBS. Objective This pilot study assessed the feasibility and acceptability of TeenLyft, an online lifestyle support program for adolescents undergoing MBS, and explored preliminary clinical and safety outcomes to inform the design of a future randomized trial. Methods Adolescents aged 13 to 18 years were recruited from a tertiary care MBS center and enrolled in TeenLyft. The study was not powered or designed as a randomized controlled trial but rather as a pilot to guide future randomized controlled trial development. Feasibility domains included recruitment, retention, data completeness, intervention fidelity, and engagement, with predefined progression criteria of ≥80% enrollment, ≥70% retention, ≥70% data completeness, and ≥90% fidelity. Exploratory clinical and safety measures (weight, BMI, and cardiometabolic markers) were collected descriptively to confirm that participation was not associated with harm. Results Twenty-nine adolescents (mean age 15.9 years, SD 1.1; n=22, 75.9% female; n=13, 44.8% Hispanic; mean BMI 47.8, SD 7.3 kg/m 2 ) were enrolled, representing 145% of the recruitment target (n=20), with 72.4% retention at 6 months. All feasibility progression criteria were met. Descriptive trends showed expected post-MBS reductions in weight and BMI and improvements in blood pressure and hemoglobin A 1c , with no adverse cardiometabolic effects observed. Conclusions TeenLyft demonstrated high feasibility, acceptability, and safety as an adjunct to adolescent MBS care. Findings support progression to a fully powered randomized trial to evaluate long-term effectiveness and sustainability.