1. There are no Class I studies or evidence-based reports that document the benefits of, or the need for, a 6 to 12 month pre-operative dietary weight loss program before bariatric surgery. The current evidence supporting preoperative weight loss involves physician-mandated weight loss to improve surgical risk or to evaluate patient adherence. Although many believe there may be benefits to acute preoperative weight loss in the weeks before bariatric surgery, the available Class II-IV data regarding acute weight loss prior to bariatric surgery are indeterminate and provide conflicting results leading to no clear consensus at this time. Preoperative weight loss that is recommended by the surgeon and/or the multi-disciplinary bariatric treatment team due to an individual patient’s needs may have value for the purposes of improving surgical risk or evaluating patient adherence, but is supported only by low-level evidence in the literature at the present time.

2. One effect of mandated preoperative weight management prior to bariatric surgery is attrition of patients from bariatric surgery programs. This barrier to care is likely related to patient inconvenience, frustration, healthcare costs and lost income due to the requirement for repeated physician visits that are not covered by health insurance.