Testing just-in-time adaptive interventions (JITAIs) to prevent goal disengagement in response to weight regain following behavioral weight loss treatment - PROJECT SUMMARY/ABSTRACT Weight regain after behavioral weight loss (BWL) treatment is extremely common and a major barrier to healthy weight control. Following BWL treatment, participants are encouraged to self-weigh daily and immediately take action to reverse small weight regains before they can escalate. However, research continually shows that, when participants notice a small weight regain, they rarely attempt to actively address it; instead, they tend to avoid the behaviors necessary to reverse the gain. Existing weight loss maintenance programs attempt to provide greater support for reversing small weight gains, typically by deploying standard BWL strategies (e.g., goal setting, problem solving) whenever participants hit a certain “red zone” weight (>5 pounds above their current weight). Yet, these programs achieve minimal or no success. Research suggests that standard BWL strategies are insufficient for helping participants reverse small weight regains because regain is demoralizing and distressing for participants, causing them to disengage from their weight control goals. My own ecological momentary assessment (EMA) research shows that participants enrolled in BWL treatment experienced greater frustration, greater shame, and lower confidence in controlling their weight on days that they gained weight, which led to poorer adherence to their weight control behaviors that day. To prevent goal disengagement, interventions must help participants cope with the distress and demoralization of weight regain. Psychological strategies of mindfulness, acceptance, and self-compassion (MASC) are commonly used in therapeutic frameworks designed to help people cope with distress (e.g., Acceptance and Commitment Therapy), and may be an especially good fit for promoting adaptive responses to weight regain. To maximize their effectiveness, these strategies must be administered immediately after the participant experiences weight regain, before the cycle of weight regain and disengagement becomes entrenched. Just-in- time adaptive interventions (JITAIs) can deploy these interventions in the moments after a weigh-in, as soon as the participant starts to disengage. The proposed study tests the feasibility, acceptability, and effectiveness of JITAIs that use both standard behavioral weight loss strategies and MASC strategies to promote adaptive responses to weight regain. Adults (N=120) who have lost at least 5% of their weight during BWL treatment will be randomly assigned to a JITAI condition or an active control (AC) condition. All participants will be asked to weigh themselves daily. Those in the JITAI condition will receive JITAIs immediately after weigh-ins that show weight gain, or on mornings they skip the weigh-in. It expected that, compared to the AC condition, participants in the JITAI condition will have improved immediate psychological and behavioral responses to weight regain (or a missed weigh-in) and ultimately, improved weight loss maintenance in the six months following BWL treatment.
