RemI for Post-Bariatric Surgery Weight Regain

The current study will evaluate a remotely-delivered acceptance-based behavioral intervention (ABTi) for individuals who are experiencing weight regain after bariatric surgery (\> 5% from their lowest postoperative weight and after postoperative Month 6). ABTi will be delivered online via interactive modules followed by brief phone calls with health coaches to reinforce the lessons over the course of 6 months. We aim to evaluate ABTi's efficacy for reversing weight regain and its effect on targeted weight control behaviors and weight related comorbidities by comparing participants randomly assigned ABTi (n = 100) to those assigned to a Control group that also receives brief phone calls but that focus on reiterating instruction on the dietary and behavioral changes required of surgery and initially taught preoperatively (C, n = 100). Assessments will be conducted at baseline, and 3, 6 (end of active treatment), and 12 months after enrollment. Seven-day, smartphone-based, Ecological Momentary Assessment (EMA) will be used at each period to precisely measure how aversive internal states drive maladaptive eating patterns that contribute to weight regain and how ABT works to interrupt these patterns to reverse risk and restore a healthy pattern of eating. The study has two primary aims and an exploratory aim. Aim 1: To compare changes in body weight over 12 months in 200 bariatric patients who have regained \> 5% of their weight and are randomly assigned to ABTi or C. (The study is powered on this outcome.) Hypothesis: Participants who receive ABTi will achieve greater reductions in weight at 12 months as compared to those who receive C. Aim 2: To compare changes in eating behaviors (i.e., caloric intake, frequency of maladaptive eating behaviors), physical activity, and weight-related comorbidities (i.e., biomarkers of diabetes, hypertension) over 12 months in the two groups. Hypothesis: Participants who receive ABTi will report lower caloric intake, greater reductions in maladaptive eating behaviors, greater increases in physical activity, and demonstrate more favorable improvements in weight-related comorbidities than those who receive C. Aim 3 (Exploratory): To test ABTi's theoretical mechanisms of action, including a) effects of theory-based active ingredients (i.e., acceptance, defusion, values clarity, mindfulness) on weight outcomes and b) changes in impact of internal states (i.e., hunger, cravings) on eating behavior. Hypotheses: a) Changes in ABT variables from baseline to mid-treatment will mediate differences in weight outcomes between conditions from midtreatment to post-treatment; b) The association between eating behavior and subjective states (i.e., hunger, cravings) will weaken in ABTi compared to C from baseline to post-treatment.