The actual weight a patient will lose after the procedure is dependent on several factors. These include:

• Patient's age
• Weight before surgery
• Overall condition of patient's health
• Surgical procedure
• Ability to exercise
• Commitment to maintaining dietary guidelines and other follow-up care
• Motivation of patient and cooperation of their family, friends and associates 

In general, weight loss surgery success is defined as achieving loss of 50% or more of excess body weight and maintaining that level for at least five years. Clinical data will vary for each of the different procedures mentioned on this site. Results may also vary by surgeon. Ask your doctor for the clinical data stating their results of the procedure they are recommending.

Studies show that at 5 years the Lap Band® achieves approximately 60-65% excess weight loss, which is comparable to the Gastric Bypass. Patients with initial higher BMIs tend to lose more total weight. Patient with lower initial BMIs will lose a greater percentage of their excess weight and will more likely come closer to their ideal body weight. Patients with Type 2 Diabetes tend to show less overall excess weight loss than patients without Type 2 Diabetes. The surgery has been found to be effective in improving and controlling many obesity related health conditions. A 2000 study of 500 patients showed that 96% of certain associated health conditions (back pain, sleep apnea, high blood pressure, diabetes, and depression) were improved or resolved. For example, many patients with Type 2 Diabetes while showing less overall excess weight loss, have demonstrated excellent resolution of their diabetic condition, to the point of having little or no need for continuing medication.