How much weight will I lose?



How much weight a patients loses after undergoing obesity surgery depends on several individual factors which can include:

  • Age
  • Current weight
  • Any prior health conditions
  • Which surgical procedure is being performed
  • Diet following surgery
  • Individual motivation and support of family and friends post-surgery

Generally, weight loss surgery is very effective and for the procedure to be considered successful, a patient will show a large reduction in weight coupled with an improvement in overall health. This encompasses the removal of previously life threatening risk factors as well as an improvement in the patient’s day to day living.

There is now over 40 years of clinical data on bariatric surgery in Australia and surgeons have plenty of data to help them determine which approach to weight loss surgery is best for patients and the reasons for their choice. There are two approaches to bariatric surgery to help people achieve their weight loss goals which are Restrictive Procedures and Malabsorptive Procedures.

Restrictive Approaches

The underlying principle of restrictive approaches to weight loss surgery is simple; if you feel full, you will not feel hunger as much and will not feel deprived of food. Restrictive approaches to weight loss surgery reduce the amount of food that can be consumed in one instance. The procedures do not interfere with the normal process of digestion. Some examples of restrictive procedures are:

Swedish Adjustable Gastric Banding (SAGB) – During the procedure, a soft band is place around the upper portion of the stomach. This divides the stomach into two sections. The small opening between the two sections allows food to pass through. Since the upper portion of the stomach fills up quickly, the patient feels full faster and will consume less food. You can find out more information and about the SAGB procedure here.

Sleeve Gastrectomy – The sleeve gastrectomy is another restrictive approach to limit the amount of food consumed since the stomach size is reduced. A small, vertical sleeve is created from the original stomach by using a stapling device. The procedure is usually performed as a keyhole surgery. You can find out more information on Sleeve Gastrectomies here.

Malabsorptive Approaches

The malabsorptive approaches to weight loss surgery alter the normal digestion of food. This causes some of the calories and other nutrients to pass through the body unabsorbed. These surgical approaches require surgery to bypass part of the small intestine where most nutrients and calories are absorbed, causing the calorie deficit. The following are examples of malabsorptive approaches:

Biliopancreatic Diversion (BPD) – During the BPD procedure, approximately three-quarters of the stomach is removed, which limits food intake and the output of stomach acid. Next, part of small intestine is divided and attached to the new, smaller stomach. Once food is consumed and digested by the stomach, it passes through the small intestines at a point where not as many calories or nutrients are absorbed. You can find more information and illustrations about BPD here.

Gastric Bypass Roux-en-Y (RYGBP) – During the RYGBP a smaller stomach is created using staples, until it holds approximately 15-20cc of contents. The remaining portion of the stomach is sealed with staples and sectioned off from the smaller pouch. The remaining portion of the stomach is left inside the body. The new stomach empties into the jejunum, which creates a calorie deficit through bypassing some of the small intestines. You can find out more about the RYGBP procedure here.

Obesity Surgery Studies

An Australian expert review of data available on the effectiveness of the various weight loss procedures available showed that: laparoscopic adjustable gastric banding, vertical banded gastroplasty and Roux-en-Y gastric bypass were all significantly effective in causing weight reduction in patients after the surgery was performed on them. Most good weight loss surgeons will have past patients you might be able to get in touch with who will happily share their success stories because of how well it worked for them.