Project Activate: Mindfulness and Acceptance Based Behavioral Treatment for Weight Loss (Activate)

Mindfulness and Acceptance based Behavioral Therapies (MABTs) are among the most promising behavioral approaches for obesity, with two recent large trials showing that they achieve better initial weight loss and/or better weight loss maintenance than does gold standard BT. However, results vary, potentially due to inconsistencies in how MABT components are utilized and emphasized. Optimizing MABTs using a typical approach, i.e., successive randomized controlled trials of various MABT packages, is slow and difficult. Multiphase Optimization Strategy (MOST) has been developed as a better method of optimizing treatment. Consistent with Phase I of MOST, we derived three MABT components from the theoretical literature. Evaluation of MABT components through a factorial design (MOST Phase II) will allow us to determine the independent and interacting efficacies of each MABT component, in addition to the identification of subsets of individuals most or least responsive to each component. Whereas mediational analyses have been inconclusive, the use of a factorial design will allow for a critical test of the main and interaction effects of individual MABT treatment components. The current study will use a full factorial design to identify the independent and combined effects of three core MABT components (Awareness, Acceptance, and Values Clarity) as additions to remotely delivered weight loss counseling. Moderators of treatment outcome (disinhibited eating, food cue susceptibility, emotional eating, delay discounting, and inhibitory control), and mediator/process variables implicated in MABTs (mindful eating, acceptance of food cues, mindfulness, body responsiveness, autonomous motivation, values clarity, hunger/satiety perceptions, and motivation and pleasure resulting from social functioning) will be assessed as well.

Obesity, Weight Loss, Behavioral treatment, Acceptance-based behavioral weight loss treatment, Acceptance and Commitment Therapy, Multiphase Optimization Strategy

Integration of acceptance and willingness skills into Standard Behavioral Weight Loss Treatment (remotely delivered).

Integration of values clarification and awareness skills into Standard Behavioral Weight Loss Treatment (remotely delivered).

Integration of mindfulness and present-moment awareness skills into Standard Behavioral Weight Loss Treatment (remotely delivered).

Measured at home using a standardized weighing procedure. Participants will be weighed in lightweight clothes without shoes using a standardized bluetooth scale accurate to 0.1 kg.

Measured at baseline, mid-treatment (6 months), post-treatment (12 months), and at 6-, 12-, and 24-month follow-up (i.e., at 0, 6, 12, 18, 24 and 36 months).

Measured at baseline, mid-treatment (6 months), post-treatment (12 months), and at 6-, 12-, and 24-month follow-up (i.e., at 0, 6, 12, 18, 24 and 36 months).

Measured in minutes per week of moderate-to-vigorous physical activity (MVPA) using the FitBit Charge 2, 3, 4, and 5, consumer-grade wrist-worn activity trackers utilized in several other studies.

Measured at baseline, mid-treatment (6 months), post-treatment (12 months), and at 6-, 12-, and 24-month follow-up (i.e., at 0, 6, 12, 18, 24 and 36 months).

Measured at baseline, mid-treatment (6 months), post-treatment (12 months), and at 6-, 12-, and 24-month follow-up (i.e., at 0, 6, 12, 18, 24 and 36 months).

Inclusion Criteria: Individuals must be of overweight or obese BMI (27-50 kg/m2) Individuals must be adults (aged 18-70) Completion of a 3-day food diary Completion of baseline assessment tasks Willingness to lose weight, be physically active, and participate in-group sessions. Participants must also provide consent for the research team to contact their personal physician if necessary to provide clearance or to consult about rapid weight gain. Exclusion Criteria: Inability to engage in physical activity (defined as walking a city block without stopping) Medical or psychiatric condition that may pose a risk to the participant during intervention, cause a change in weight, or limit ability to comply with the program Recently began or changed the dose of a medication that can cause significant change in weight History of bariatric surgery; weight loss of > 5% in the previous 3 months Currently pregnant or breastfeeding or planning to become pregnant Planning to, or participating in, another weight loss treatment in the next 3 years. Engaging in compensatory vomiting, other severe compensatory behaviors, or more than 12 of any compensatory behavior in the previous 3 months Experiencing significant loss of control eating (9 or more binge episodes in the previous 3 months)