The purpose of the trial is to determine whether a preoperative lifestyle intervention (targeting diet, exercise, and preparation for surgery) will favorably impact obesity-related parameters prior to bariatric surgery and improve short-term postoperative outcomes.

This is a randomized, controlled trial to evaluate the impact of a preoperative lifestyle intervention that targets diet, exercise, and preparation for surgery as an adjunct to the surgical treatment of obesity. Patients will be randomized to a 6-month lifestyle intervention (n = 100) or to usual care (n = 100) prior to undergoing bariatric surgery. We aim to evaluate the effect of the intervention on select pre- and postoperative outcomes. We hypothesize that patients who participate in the preoperative intervention will exhibit greater improvements in weight and related outcomes and better preparation for surgery than those who receive usual care. After operation, we hypothesize that patients who participate in the intervention will exhibit better compliance and fewer behavior-related eating problems, as well as a lower rate of complications and fewer outpatient visits with surgery-related conditions than those who received usual preoperative care. Our secondary aim is to determine whether the intervention affects weight/BMI trajectory through 24 months after operation.

Inclusion Criteria:

• Any candidate for weight loss surgery who is at least 18 years old [At the University of Pittsburgh Medical Center, bariatric surgery is recommended as a treatment for individuals with Class III obesity (BMI > 40), or Class II obesity (BMI 35- 40) and serious obesity-related health problems]

Exclusion Criteria:

• Mental retardation or psychosis
• Previously diagnosed genetic obesity syndrome
• Participation in a structured weight management program in the 6 months prior to study enrollment
• Uncontrolled psychiatric symptomatology sufficiently severe to require immediate treatment
• Pregnant or lactating in the previous 6 months
• Taking a medication known to affect body weight such as oral steroids in the previous 6 months
• Any previous surgery for weight loss
• Deemed high risk surgical candidate.