Study: NCT03704064

Intervention type: BEHAVIORAL
Group type: EXPERIMENTAL
Intervention: Stigma-Reduction Intervention
Description: Session topics will be based on those tested in a previous pilot study, including: psychoeducation about weight and weight stigma; challenging myths and cognitive distortions related to weight; strategies for coping with instances of stigma; and increasing empowerment and body esteem. The effects of weight stigma on health behaviors will be discussed, and sessions will focus specifically on helping participants overcome stigma-related barriers to physical activity. For example, they will be given strategies to cope with anticipated stigma while exercising in public spaces (e.g., while walking), as well as to challenge self-critical beliefs (e.g., that they are lazy) which may otherwise lead them to avoid exercising. These concrete strategies, along with reducing WBI and improving self-confidence, are intended to increase participants' self-efficacy for and engagement in physical activity.

Intervention type: BEHAVIORAL
Group type: ACTIVE_COMPARATOR
Intervention: Behavioral Weight Loss (BWL)
Description: This intervention will be based on the Diabetes Prevention Program. A diet of 1200-1499 calories per day will be prescribed for participants \< 250 lb, and 1500-1800 for those ≥ 250 lb. Participants will be instructed to eat a balanced deficit diet. Session topics during the first 20 weeks will include self-monitoring, stimulus control, social support, portion sizes, and goal-setting. Those during weeks 21-72 will focus on skills required for weight loss maintenance and relapse prevention. Physical activity will be begin with a prescription of 60 min/wk, and will gradually progress by 10 minutes over 2-4 week intervals until achieving 150 min/wk by week 20, 200 min/wk by week 46, and 250 min/wk by week 72. Participants will be instructed to spread the activity equally across at least 5 days in bouts that are \>10 minutes in duration. Moderate intensity will be prescribed with an emphasis on walking; the vast majority of our research participants self-select this form of activity.

Intervention type: BEHAVIORAL
Group type: EXPERIMENTAL
Intervention: Behavioral Weight Loss (BWL)
Description: This intervention will be based on the Diabetes Prevention Program. A diet of 1200-1499 calories per day will be prescribed for participants \< 250 lb, and 1500-1800 for those ≥ 250 lb. Participants will be instructed to eat a balanced deficit diet. Session topics during the first 20 weeks will include self-monitoring, stimulus control, social support, portion sizes, and goal-setting. Those during weeks 21-72 will focus on skills required for weight loss maintenance and relapse prevention. Physical activity will be begin with a prescription of 60 min/wk, and will gradually progress by 10 minutes over 2-4 week intervals until achieving 150 min/wk by week 20, 200 min/wk by week 46, and 250 min/wk by week 72. Participants will be instructed to spread the activity equally across at least 5 days in bouts that are \>10 minutes in duration. Moderate intensity will be prescribed with an emphasis on walking; the vast majority of our research participants self-select this form of activity.