US researchers have identified two factors; diabetes and post-surgical pouch size as the decisive factors of weight loss in patient of post gastric bypass. Initial BMI, sociodemographic variables, other obesity-related comorbidities, and surgical factors - including surgical approach, gastrojejunostomy technique, and alimentary limb length - were not associated with weight loss outcomes.
In multivariate analysis, only the presence of diabetes (odds ratio 3.09, p = 0.007) and larger pouch size (OR 2.77, p < 0.001 per standard deviation) were independently associated with poor weight loss.
The team examined factors related to weight loss 12 months after gastric bypass surgery for 310 patients treated at their tertiary referral center between 2003 and 2006. Average age was 45 years, and mean preoperative BMI was 52. According to the report, the overall mean excess weight loss at one year was 60 per cent, resulting in a mean BMI of 34.
Moreover, they conclude, that detailed attention to the creation of a small gastric pouch is essential for achieving the best results.