RESUMO
BACKGROUND: Gastric bypass is the bariatric surgery most frequently performed in the world. It is responsible for sustainable weight loss, resolution of comorbidities, and improvement of quality of life. However, weight loss is not homogeneous, at times being insufficient in some patients. Our objective was to assess which factors were important in influencing this differentiated weight loss over a period of 4 years after surgery. METHODS: In this retrospective study, we assessed several physical, socioeconomic, behavioral, surgical, and demographic factors in morbidly obese patients submitted to Roux-en-Y gastric bypass that might influence excess weight loss over a period of 4 years after surgery. The same factors were assessed in order to characterize insufficient excess weight loss (<50% EWL). RESULTS: Review of the medical records of 149 patients showed that type-2 diabetes mellitus and dyslipidemia were the most important factors related to a lower EWL up to the third year. Preoperative weight loss, lower schooling, and lack of adherence to nutritional guidelines were important after 2 and 3 years. The presence of depression and lack of adherence to nutritional guidelines were the factors related to EWL of less than 50%. CONCLUSIONS: Special attention and clarification should be provided to patients with diabetes mellitus type 2 and dyslipidemia and to patients with depression and lower schooling, since these patients tend to lose less excess weight after surgery. Multiprofessional care should also be provided so that the patients will follow nutritional guidelines more rigorously after surgery.