Testing Just-in-Time Adaptive Interventions (JITAIs) to Prevent Goal Disengagement in Response to Weight Regain

Participants in this condition will receive a 6-month weight loss maintenance intervention that uses mindfulness, acceptance, and self-compassion strategies to respond to weight regain.

Behavioral: JITAI Combined with psychological intervention

Participants in this condition will receive minimal intervention designed to reflect "usual care" for weight loss maintenance.

Behavioral: Active Control

For six months, participants will receive a just-in-time adaptive interventions via a smartphone app immediately after they gain weight or they skip a weigh-in (according to a specific algorithm). Interventions will engage participants in mindfulness, acceptance, and self-compassion-based (MASC) strategies through different modalities (e.g., writing exercises, videos, audio reflections). They will take approximately 1-10 minutes. Participants will also attend an introductory workshop, during which they will receive the instructions weigh daily, learn the importance of quickly responding to weight regain, and be introduced to MASC strategies. They will also attend two booster workshops during the 6-month period.

For six months, participants will receive weekly, automated messages via a smartphone app with reminders of standard behavioral weight control principles. Participants will attend an introductory workshop, during which they will receive instructions to weigh daily and learn the importance of responding to weight regain.

Plazo: Whenever participants skip a weigh-in or regain weight during the 6 month study period

Through ecological assessment surveys, participants will respond to a single item measuring their current negative affect.

Plazo: Whenever participants skip a weigh-in or regain weight during the 6 month study period

Through ecological assessment surveys, participants will respond to a single item measuring their current shame.

Plazo: Whenever participants skip a weigh-in or regain weight during the 6 month study period

Through ecological assessment surveys, participants will respond to a single item measuring their current feelings of motivation.

Plazo: Whenever participants skip a weigh-in or regain weight during the 6 month study period

Through ecological assessment surveys, participants will respond to a single item measuring their current self-efficacy.

Plazo: Whenever participants skip a weigh-in or regain weight during the 6 month study period

Through ecological assessment surveys, participants will respond to a single item measuring their current confidence in the effectiveness of weight control behaviors.

Plazo: Whenever participants skip a weigh-in or regain weight during the 6 month study period

Through ecological assessment surveys, participants will respond to a single item measuring their state self-compassion.

Plazo: Whenever participants skip a weigh-in or regain weight during the 6 month study period

Through ecological assessment surveys, participants will respond to a single item measuring their state mindfulness.

Plazo: Whenever participants skip a weigh-in or regain weight during the 6 month study period

Through ecological assessment surveys, participants will respond to a single item measuring their state acceptance.

Plazo: Whenever participants regain weight during the 6 month study period

Through ecological assessment surveys, participants will respond to a single item measuring their self-serving interpretation of the weight regain.

Plazo: Whenever participants skip a weigh-in or regain weight during the 6 month study period

Whether participants log their calories (at least 800 calories) using a dietary tracking app that day (yes/no).

Plazo: Whenever participants skip a weigh-in or regain weight during the 6 month study period

Minutes of moderate-to-vigorous physical activity they engage in that day, as tracked by their Fitbit band.

Plazo: Whenever participants skip a weigh-in or regain weight during the 6 month study period

Likelihood that participants weigh themselves the following day on a wireless smart scale (yes/no).

Plazo: End of treatment (6 months after baseline)

Using participants' weights from a wireless scale, their percent weight change from the beginning to the end of the study period will be calculated.

Plazo: End of treatment (6 months after baseline)

Intervention acceptability will be operationalized as the percent of participants who indicate that they are "satisfied" or "very satisfied" with the program on an anonymous survey that they complete during their individual interview.

Plazo: 6 months (duration of study period)

The number of days that participants logged their calories (at least 800 calories) using a dietary tracking app during the study period.

Plazo: 6 months (duration of study period)

Average total minutes of weekly moderate-to-vigorous physical activity, as tracked by their Fitbit band, during the study period.

Plazo: 6 months (duration of study period)

Total number of days that participants weighed themselves on a wireless smart scale during the study period.

Plazo: Mid-Treatment (3 months after baseline)

Participants will self-report their mindfulness using the Awareness subscale of The Philadelphia Mindfulness Scale. The range of scores is 1-5, with higher scores indicating greater mindfulness.

Plazo: Mid-Treatment (3 months after baseline)

Participants will self-report their mindful acceptance using the Acceptance subscale of The Philadelphia Mindfulness Scale. The range of scores is 1-5, with higher scores indicating greater mindful acceptance.

Plazo: Mid-Treatment (3 months after baseline)

Participants will report their self-compassion using the Self-Compassion Scale Short Form. Scores can range from 1 to 5, with higher scores indicating higher self-compassion.

Testing Just-in-Time Adaptive Interventions (JITAIs) to Prevent Goal Disengagement in Response to Weight Regain