The gastric sleeve surgery can help individuals lose a significant amount of weight. On average, patients can expect to lose about 50-70% of their excess body weight within the first two years following the procedure. The amount of weight loss can vary depending on factors such as individual metabolism, adherence to post-operative guidelines, and lifestyle changes. It's important to remember that the gastric sleeve is not a magic solution, but rather a tool that, when combined with healthy habits, can support sustainable weight loss and improve overall health.