Bariatric Journal

Average Weight Loss With Gastric Banding Surgery

What is the typical average weight loss with Gastric Banding Surgery?

Laparoscopic gastric banding also is known as “laparoscopic adjustable gastric banding” is a restrictive bariatric (weight loss surgery) that is commonly performed as a form of surgical management of obesity. It has additional advantages of being safer, cheaper, and relatively reversible. It is also associated with lesser post-operative complication and length of hospital stay.

The surgery involves the compartmentalization of the stomach into a smaller upper pouch and a more substantial lower pouch with the use of an adjustable silicone band. This is done in such a way that the two pouches still communicate with each order. The silicone band is inflated with sterile water, and the quantity of the water can be adjusted through a catheter (tube) that extends from the group to an area slightly under the skin of the abdomen.

The smaller upper pouch accommodates a small amount of food and causes early satiety during the meal. This leads to reduced food intake and subsequent weight loss. The lower larger pouch only serves as a conduit for the food coming from the upper pouch en route to the intestine.

The primary goal of all bariatric surgeries is to achieve a significant weight loss. Though this varies from one type of operation to the other and also depends on the adherence to post-operative dietary and exercise plans.

The weight loss following bariatric surgery is usually calculated as the percentage of excess weight loss %age EWL) or the percentage total weight loss (%age TWL) or the reduction in body mass index (BMI). These are calculated as follows:

%age excess weight loss = excess weight before surgery – excess weight after surgery ₓ 100

Excess weight before surgery

Excess weight loss is the measured weight minus the ideal weight. The ideal weight is the weight which when combined with the height will give a BMI of <25kg/m2.

%age TWL= weight before the surgery – influence at a particular time after the surgery

Weight before the surgery

To calculate the Body Mass Index (BMI), the weight is measured and recorded in a kilogram, while the height is measured in meters. The pressure is then divided by the square of the height.

BMI = Weight (kg)

Height2 (m2)

In a study that involved 2,815 patients, with an average body mass index of 44.6 kg/m2, who had laparoscopic gastric banding and were followed-up for 5years, the average percentage weight loss (%TWL) and percentage excess weight loss (%EWL) progressively increased over the first 2.5 years post-surgery and reached a plateau at 20% and 49 %, respectively, for up to 5 years of follow up.1

An average body mass index reduction from 44.3kg/m 2 to 34.2, 32.8, and 31.9, at 1year, 2year and 3years after the surgery respectively was reported in over 500 cases of gastric banding surgery.2

A similar result was obtained in 178 patients who had laparoscopic gastric banding.  The average percentage total body weight loss at 1, 2 and three years after surgery was 15.8%, 20.7%, and 20.3%, respectively.3

A study conducted by Lehmann et al. involving 202 patients compared the effect of gastric banding and gastric sleeve surgery on weight loss. One hundred and thirty of these patients had laparoscopic adjustable gastric banding while the remaining 72 had gastric sleeve surgery. The average percentage excess weight loss (%age EWL) in those who had banding at 6months and 12months post-surgery were 30.1% and 34.6% respectively.4

From the above studies, it can be concluded that following laparoscopic gastric banding, an individual is expected to lose about 20% of the pre-operative weight, about 45% of the excess body weight before surgery and the BMI is expected to reduce by an average of 13. Thus if you are 120kg before surgery and the BMI is 40%, it is expected that you should lose about 24kg and the MBI should be around 27.

Additional Resources:

  1. Gastric Banding Surgery Overview
  2. Cost of  Gastric Banding Surgery


  1. Cobourn C, Chapman MA, Ali A, Amrhein J. Five-Year Weight Loss Experience of Outpatients Receiving Laparoscopic Adjustable Gastric Band Surgery. Obesity Surgery. 2013;23(7):903-910. doi:10.1007/s11695-013-0881-7.
  2. Zinzindohoue F, Chevallier J, Douard R et al. Laparoscopic Gastric Banding: A Minimally Invasive Surgical Treatment for Morbid Obesity. Annals of Surgery. 2003;237(1):1-9. doi:10.1097/00000658-200301000-00001.
  3. Chiu CJ, Birch DW, Shi X, Karmali S. Outcomes of the adjustable gastric band in a publicly funded obesity program. Canadian Journal of Surgery. 2013;56(4):233-236. doi:10.1503/cjs.002712
  4. Lehmann A, Bobowicz M, Lech P, et al. Comparison of percentage excess weight loss after laparoscopic sleeve gastrectomy and laparoscopic adjustable gastric banding. Videosurgery and other Miniinvasive Techniques. 2014;9(3):351-356. doi:10.5114/wiitm.2014.44257.

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