The role of dumping syndrome in weight loss after gastric bypass surgery

Background: Roux-en-Y gastric bypass is the most commonly performed operation for the treatment of morbid obesity in the US. Dumping syndrome is an expected and desired part of the behavior modification caused by gastric bypass surgery; it can deter patients from consuming energy-dense food. In this study we assessed the role dumping has in weight loss and its relationship with the patient's eating behavior. Methods: Fifty patients who underwent gastric bypass between January 2008 and June 2008 were enrolled. Two questionnaires, the dumping syndrome questionnaire and the Three-Factor Eating Questionnaire (TFEQ), were used to record the patients' responses. The diagnosis of dumping syndrome was based on the Sigstad scoring system, where a score of 7 and above was considered positive. TFEQ evaluated the patients' eating behavior under three scales: cognitive restraint, uncontrolled eating, and emotional eating. The results were analyzed with descriptive and parametric statistics where applicable. Results: The prevalence of dumping syndrome was 42 %, with 66.7 % of the subjects being women. The nondumpers were observed to have a greater mean decrease in body mass index than the dumpers at 1 and 2 years (18.5 and 17.8 vs. 14.4 and 13.7 respectively). There was no definite relationship between the presence of dumping syndrome and the eating behavior of the patient. However, the cognitive restraint scores, greater than 80 %, were associated with an average decrease in BMI of 19 and 20.8 at 1 and 2 years compared with 14.6 and 12.4 in those with scores less than 80 % (p = 0.01 and p = 0.03, respectively). Conclusion: The presence of dumping syndrome after gastric bypass does not influence weight loss, though eating behaviors may directly influence it.