Benefits of surgery
The extent of weight loss can be 30-40% of body weight (35-45 kg for a 120kg person). Most of the weight loss occurs during the first year after the operation. There may be some further weight loss during the second year and a plateau is then reached. The true benefit of surgery is better measured in terms of the cure of obesity-related illnesses and improvement in quality of life. The most dramatic effect is on diabetes - diabetes is cured (i.e. blood sugar remains normal without any medication) in 80% of diabetic patients. High blood pressure and high cholesterol may be cured in 60-80% of patients. Even if the disease is not completely cured, it often becomes less severe and is better controlled with less medication. Marked improvement or cure is also seen in cases of fatty liver, obstructive sleep apnea, obesity hypoventilation and infertility. Treatment of obesity can help with arthritis (joint pains) and reduce the risk of several cancers and heart attack. Large studies have shown that bypass patients live considerably longer than obese persons who did not have surgery.
Long-term success of surgery: What is the chance of weight re-gain?
The majority of bariatric surgery patients maintain the weight loss, lifelong. A healthy diet and regular exercise are very important for long-term success in weight-control. Large studies have shown that about 25% of patients do regain some of the lost weight, during long-term follow-up. The weight regain is usually partial (e.g. a person, who originally lost 45 kg, regains 10 kg at 8 years after the operation) so that a large part of the benefit of bariatric surgery is maintained. There can be several causes for weight regain: often, there is failure to follow the advice of the doctor or dietician. Structural problems, such as widening of the reduced stomach, are uncommon after gastric bypass or sleeve gastrectomy but can occur - in such cases, further surgery (called “revisional surgery”) or endoscopy procedures are available.
Potential risks of surgery
Obesity surgery can be conducted very safely. But, like any major operation on the human body, there is some risk of side-effects and complications. Risks can vary for individual patients, depending on their age, weight, obesity-related illnesses, past medical history and type of operation. Scoring systems have been developed to estimate the risk of surgery for individual patients and need to be discussed in detail during a consultation with the surgeon.