Bariatric Journal

Weight Regain after Gastric Bypass Surgery

What are your options if you regain weight after gastric bypass surgery?

Gastric Bypass Surgery is successful for 90% of patients, but some have the possibility of poor weight loss. What is the cause and possible solutions to weight regain after surgery?

Due to the increase in associated disease conditions, and its consequences on the quality of life and lifespan, obesity has remained a thing of concern among the affected population. The etiology of excess fat deposition involves the interaction between the genetic make-up of an individual and the environmental factors. These environmental factors include unhealthy diet, excess calorie intake, inadequate physical activity, etc.

Treatment of obesity is initiated with the use of dietary modification and increase in physical activity. This can be supported with medications. However, the results of these treatments are often not satisfactory especially in those that are morbidly obese (BMI≥40). Also the weight regain after cessation of these intervention is almost invariable.

Bariatric surgeries have now become the treatment of choice for those with morbid obesity and those who desire a significant improvement in the associated disease conditions. These surgeries are broadly divided into two groups namely the restrictive and the malabsorptive procedures.

Although there is an associated risk of weight regain after these surgeries but this is relative and not absolute. With certain precautions the weight regain after bariatric surgery can be prevented.

Gastric bypass surgery (laparoscopic Roux-en-Y gastric bypass) is a commonly performed bariatric procedure for morbidly obese individuals. It involves the surgical partitioning of the stomach in such a way as to create a smaller upper pouch and a larger lower pouch using surgical staples. The upper pouch becomes the functioning stomach accommodating little amount of food leading to early sensation of fullness. The lower pouch is made non-functional.

The small intestine is then divided at about 45cm from the lower stomach pouch and the distal end is connected to the smaller upper pouch while the proximal end is connected to the small intestine at about 100cm below the point of division. This reduces the amount of nutrients that is absorbed.

The effectiveness of this surgical procedure is partially dependent on the compliance of the patient to dietary plan and physical activities recommended by the dietician and the surgeon. It is possible to experience weight gain after an initial weight loss following gastric bypass surgery. The maximal weight loss is often recorded at 24 months post-surgery after which the weight loss becomes insignificant.1 Weight regain is often noticed between 24months and 60months.1

There is no generally accepted definition or criteria for substantial weight regain. However, different studies use different descriptions, which are based on kilograms, body mass index (BMI) units or % excess weight loss (EWL) gained.2

Factors responsible for weight regain are non-adherence to the dietary plan, lack of physical activities, stretching and dilatation of the upper gastric pouch, and development of an abnormal connection between the upper and the lower gastric pouches.

The stomach lining has the tendency to stretch due to the presence of multiple folds. Following the gastric bypass surgery, the upper pouch of the stomach can only accommodate small amount of food. This leads to feeling of fullness and the appropriate response is to stop eating. However if you ignore this feeling and continue to eat, the stomach gradually expands and over time becomes bigger accommodating progressively large quantity of foods. This then abolishes the restrictive aspect of the gastric bypass surgery with the consequence of weight regain.

Although many options are available to correct this abnormality such as pouch resetting or revision surgeries, there effectiveness in achieving a significant weight loss is variable. It also implies increase cost of care as some of these corrective procedures are even costlier than the initial procedure.

Part of major risk factors for the development of obesity is unhealthy diet and excess calorie intake. Obese individuals are often counseled on dietary adjustment before undergoing bariatric surgery. Some are made to institute a healthy dietary plan before surgery in other to increase the chance of compliance after surgery. Non-adherence to the dietary plan may prevent optimal weight loss or cause weight regains following gastric bypass surgery.

Lack of/ inadequate physical activity is another factor responsible for weight regain.  Patients are advised to commence exercise as soon as possible after bariatric surgery and to gradually move from low intensity to high intensity ones. Although there is no consensus on how much physical activity is adequate to prevent weight regain, however, there is evidence that only 10–24% of patients after laparoscopic Roux-en-Y gastric bypass are able to meet minimal physical activity recommendations for general health promotion.2

Communication between the stomach pouch and the remnant stomach (gastro-gastric fistula) leads to movement of food materials into the remnant stomach. This abolishes the restrictive and the malabsorptive functions of the gastric bypass surgery.

Weight regain after gastric bypass is a possibility but not an absolute occurrence. Adherence to the dietary plan, adequate exercise, getting the best of surgeon to do the surgery  are some of the preventive measures that can be taken to reduce the risk of weight regain after gastric bypass,

Additional Resources

  1. Costs of Gastric Bypass Surgery
  2. Gastric Bypass Surgery


  1. Magro D, Geloneze B, Delfini R, Pareja B, Callejas F, Pareja J. Long-term Weight Regain after Gastric Bypass: A 5-year Prospective Study. Obesity Surgery. 2008;18(6):648-651. doi:10.1007/s11695-007-9265-1.
  2. Maleckas A, Gudaitytė R, Petereit R, Venclauskas L, Veličkienė D. Weight regain after gastric bypass: etiology and treatment options. Gland Surgery. 2016;5(6):617-624. doi:10.21037/gs.2016.12.02.

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