For the growing number of severely obese individuals, there are currently few effective long-term weight control options with the exception of bariatric surgery. However, behavioral factors including low physical activity can undermine successful surgical outcomes. This study will compare the effects of a behavioral physical activity intervention with a standard care control condition on changes in physical activity among inactive adult bariatric surgery patients.

The proportion of Americans who are severly obese or more than 100 pounds overweight is rapidly increasing. This presents a significant public health challenge as severely obese individuals have a higher rate of comorbidities and exact a greater toll on the health care system than less obese persons. For these individuals, bariatric surgery is currently the treatment of choice for producing substantial and long-term weight loss, although outcomes vary. Low physical activity is one behavioral factor that undermines surgical success. However, structured behavioral interventions to increase physical activity in bariatric surgery patients have not been conducted.

This study involves a randomized controlled trial that compares the effects of a behavioral intervention to increase physical activity with a standard care control group on changes in physical activity among adult bariatric surgery patients with low physical activity. Eighty bariatric surgery patients will be assigned to 6 weeks of either preoperative: (1) intervention to increase physical activity or (2) standard care control. Participants in the intervention group will receive individual, face-to-face sessions involving tailored instruction in use of standard behavior change strategies such as self-monitoring, goal setting and stimulus control. The PA intervention will focus on increasing home-based walking exercise. Physical activity will be objectively measured for 7 consecutive days via accelerometry at baseline/pre-intervention, post-intervention, and 3- and 6-months postoperative follow-up. At each time point, the groups will be compared on total moderate-to-vigorous physical activity (MVPA) minutes and MVPA minutes occurring in bouts of 10 minutes or longer. This study will test whether the behavioral physical activity intervention produces greater increases in pre- and post-operative physical activity than standard care. The long-term goal of this research is to improve bariatric surgery outcomes through innovative behavioral strategies to increase physical activity.

Inclusion Criteria:

• BMI equal to or greater than 40 or greater than or equal to 35 (in presence of significant comorbidities)
• Have elected to undergo Roux-en-Y gastric bypass or laparoscopic adjustable gastric banding
• Able to engage in activities of daily living
• Currently inactive, defined as less than 150 weekly minutes of moderate-to-vigorous physical activity in bouts of 10 minutes or more
• Obtainment of written consent from surgeon to participate

Exclusion Criteria:

• Unable to engage in activities of daily living
• Report conditions that would render the participant unlikely to follow the study protocol (e.g., relocation, substance abuse, severe psychiatric condition)
• Inability to understand program instructions due to language barrier or a mental disability