Bariatric surgery is a commonly performed surgical procedure for control of morbid obesity. Its use has continued to grow with a total of 196,000 bariatric surgery procedures performed in 2015, a significant increase from 158,000 in 2011 [1]. Gastric bypass, including Roux-en-Y and duodenal switch, are some of the most common forms of bariatric surgery. To optimize weight loss after bypass, patients should undergo careful selection, teaching, biochemical testing, psychiatric evaluation, nutritional assessment, and diet changes.