The initial weight loss after sleeve gastrectomy loss is similar to the gastric bypass. The vast majority of patients lose 50 to 80% of their excess weight in the first 12 months. With the roux-en-y gastric bypass, most patients keep 50% to 70% of their excess weight off after 10 years.
However, some patients can regain some or much of their original weight. This means a person who is 300 pounds and has an ideal body weight of 150 pounds can expect to be between 180 to 225 pounds at the end of ten years.
As of 2009, the 3 year weight loss results of the gastric sleeve seem similar to the gastric bypass. However,in the past, purely restrictive operations have led to LESS long term weight loss than the gastric bypass.
Thus, at this time it is unclear if patients will maintain the same long term weight loss after 10 years that has been observed with the gastric bypass. For this reason, despite its increasing popularity, it cannot be considered the gold standard for weight loss operations.
Like the gastric bypass, it is easily possible to regain all the weight if changes in eating habits and exercise have not been implemented.