BackgroundLaparoscopic sleeve gastrectomy (LSG) is a relatively new surgical technique for the treatment of morbid obesity. It is unclear whether the volume of the gastric remnant can expand after surgery as a result of intraluminal pressure maintained over time. If this were the case, the increased volume could affect weight loss and the improvement in comorbidities. This study aims to assess the evolution of residual gastric volume (RGV) during the first year after LSG and its relationship with weight loss.