Why Did I Gain Weight After Gastric Bypass Surgery?

Dr. Christopher McGowan
February 9, 2021

Each year, over 200,000 Americans elect to have gastric bypass surgery in the hope of finally making noticeable progress toward losing weight. Gastric bypass is by far the most common type of bariatric surgery, and many people choose it because of the perceived potential for losing a significant amount of weight in a relatively short time frame. Many people do indeed find success with gastric bypass in the short term, but a majority of participants unfortunately regain much of the weight they lost. 

In fact, one study indicated that 59% of people regained 20% or more of the weight they originally lost after surgery. Some of these gains can be explained by personal choices on the part of the patient, but it also can be due to technical complications of the surgery itself. Though these complications can be resolved by one of True You’s signature offerings (a procedure called gastric bypass revision), it is helpful for anyone contemplating gastric bypass to really understand what is involved in the surgery and why it sometimes stops working.

What is Gastric Bypass Surgery?

There are actually several types of this kind of bariatric surgery, but the most commonly used type is known as Roux-en-Y gastric bypass, named after the surgeon who first developed it. This laparoscopic surgery involves dividing the stomach into two parts: a small, egg-sized section (also known as the gastric pouch) and the larger remaining volume (gastric remnant) that is bypassed. The ultimate goal of the surgery is to limit stomach volume so that you literally can’t eat as much food; over time, this limit is meant to force you to eat fewer calories and thus lose weight.   

Some other forms of weight loss surgery seek to either limit total calorie intake or reduce the absorption rate of nutrients in the small intestine. One of the reasons gastric bypass is purportedly more effective than other methods is that it uses both of these approaches in the same surgical procedure. The combination of overall lower calorie intake and reduced absorption of nutrients has a beneficial impact on the hormones responsible for the feelings of hunger and satiety. These hormonal changes can actually help you find long-term success in modifying your eating habits so that “being full” gets redefined at a lower calorie count.

The way this is achieved in gastric bypass comes down to the nature of how the stomach is divided and bypassed. The small gastric pouch created from the stomach gets separated and reconnected to a segment of the small intestine called the jejunum. This allows food to enter the new, smaller gastric pouch and bypass the gastric remnant and duodenum. The primary benefit of bypassing the duodenum is to avoid the major nutrient absorption that normally happens there. In Roux-en-Y gastric bypass, food moves directly into the jejunum from the stomach pouch and then onto the rest of the small intestine. 

The remaining bulk of the stomach and duodenum is closed off so that no food can enter. The duodenum (with gastric remnant attached) is then reattached to the small intestine further down the line. The reason for reattaching the stomach and duodenum—rather than just removing it completely—is so the beneficial digestive juices generated by the stomach, pancreas, and liver still are able to interact with food that is passing through the small intestine. But because a significant section of the small intestine is bypassed, fewer nutrients (and therefore calories) are absorbed by the body.  

Who Can Benefit From Gastric Bypass Surgery?

In general, gastric bypass is meant for people who have a body mass index (BMI) of over 35 with obesity-related health problems (like type 2 diabetes or heart disease) or a BMI of over 40 even if the patient doesn’t have obesity-related health problems. Additionally, bariatric surgeries like gastric bypass are usually recommended if the patient has not had success losing weight through traditional methods such as a modified diet and/or an exercise plan. Unfortunately, even some people who would otherwise be good candidates based on BMI don’t qualify for the procedure because of the risks associated with surgery. 

Reasons for Weight Regain After Gastric Bypass Surgery

Gastric bypass surgery requires a serious commitment in order to be successful because of the surgical risks, recovery time, and necessary lifestyle changes. While it remains a relatively safe procedure, it is nevertheless complex with a lot of different factors contributing to whether or not you can lose weight and keep it off. As noted earlier, many people lose weight initially but end up gaining that weight back within a couple years. There are numerous reasons why this might happen or factors that might contribute:  

Prior Weight: Gastric bypass surgery patients are usually encouraged to lose some weight before the surgery in order to reduce the chance of surgical complications and to begin to make the kind of lifestyle adjustments that are necessary for sustained weight loss. Patients who aren’t successful at losing some weight initially tend to be more likely to regain weight after surgery.

Lifestyle/Behavior: Some people who opt for gastric bypass surgery just aren’t truly committed to the process and therefore don’t make the necessary changes. Those with binge eating disorder (BED) are especially vulnerable to experiencing weight regain. In addition to having a poor diet and low physical activity, some patients also turn to alcohol or drug abuse; besides the potential for associated negative eating habits, alcohol and drug abuse can cause significant complications in terms of the actual surgery.

Mental Health: An issue often closely related to lifestyle and behavior issues is mental health. Beyond the well understood physical health concerns associated with obesity, it also has many psychological and emotional components. Someone who already has depression, for example, may continue to struggle if weight loss isn’t as dramatic or timely as expected. These factors, combined with a possible lack of a social support group, can make weight regain more likely in the years following surgery. Old habits and food addiction may return and create a spiraling effect that leads to more weight gain and more depression.

Medical/Surgical: Some reasons for weight regain after surgery are totally unrelated to the lifestyle choices and behaviors of the patient. Some common issues that may come up include: 

  • Gastrogastric Fistula: Usually a complication related to a gastric bypass with a non-divided pouch rather than a divided pouch, a gastrogastric fistula is a condition where food materials leak from the gastric pouch to the gastric remnant. When this happens, more food is digested and more nutrients are absorbed by the body. 
  • Stoma Dilatation: Known to doctors as “progressive dilatation of the gastrojejunal stoma,” this complicated set of terms means that the passageway between the gastric pouch and the rest of the digestive system has dilated, or grown larger. As it grows larger, more food can pass more quickly and the patient will feel full slower. 
  • Pouch Enlargement: Sometimes the gastric pouch itself can grow larger over time for a number of different reasons. As the pouch expands in size, it can hold more and more food, making the feelings of satiety happen more slowly. Over time, this can lead to the patient inadvertently overeating.  

Gastric Bypass Revision

The causes of weight regain related to a person’s lifestyle are challenging but preventable with support from family and friends, but the medical causes of course require a different approach. For those who have experienced gradual weight regain even when they’ve done everything right, sometimes a modification of the original surgery is required. The procedure used to “reset” a bypass is called gastric bypass revision. True You is pleased to offer this procedure for motivated individuals who previously had gastric bypass and are now experiencing weight regain.

Even though the original gastric bypass was done surgically, True You can perform a revision endoscopically and without the need for any incisions. The most common reasons for a revision is either an enlarged gastric pouch or an enlarged opening between the gastric pouch and the small intestine (known as gastrojejunal anastomosis). To resolve the problem, we use an endoscope to reduce the size of the pouch or the opening through carefully placed sutures. With the reduced pouch size, it allows the gastric bypass to function the same way it did when the surgery was first completed. 

Does Bariatric Revision Work?

Most bariatric patients who have gastric bypass surgery lose at least 50% of their excess body weight within the first year or two after the surgery. If they regain some of that weight later on primarily because of lifestyle factors, a gastric bypass revision won’t really help. But if the weight regain was related to an enlarged hole in the gastric pouch, it’s possible to lose the excess weight that was regained. In fact, according to True You’s data, gastric bypass revision patients typically lose around 10% of their body weight, and the weight generally stays off.

True You Offers Alternatives to Gastric Bypass

Gastric bypass surgery is sometimes referred to as the “gold standard” of bariatric surgery because of the consistent results and the relatively low risk of major complications. But as potentially beneficial as the surgery can be, there are always risks associated with surgery; this is especially true for obese adults who may already have underlying health issues. Moreover, even when the surgery is a “success,” there is still potential for weight gain.

At True You, we understand how challenging it can be to lose weight. In a world where fad dieting and unsustainable exercise regimens are often put forward as the only ways to lose weight, we offer state-of-the-art, non-surgical solutions that can give you comparable results to bariatric surgery without the risks and complexities of actual surgery. If you’ve already had gastric bypass surgery and have experienced weight regain, our revision procedure can help get you back to where you started when you first got the surgery.

If you’re still assessing your options for how to achieve your weight loss goals, however, we would love to hear from you! In addition to gastric bypass revision, True You offers several other non-surgical weight loss solutions like ORBERA®, and endoscopic sleeve gastroplasty (ESG). Contact us today to request a consultation. Freedom is waiting!

Dr. Christopher McGowan
Dr. Christopher McGowan

Dr. Christopher McGowan, MD, a leader in endobariatrics, specializes in non-surgical obesity treatments and is triple-board-certified in Internal Medicine, Gastroenterology, and Obesity Medicine. Renowned for pioneering endoscopic sleeve gastroplasty (ESG) with over 2,000 procedures, his global influence and research contributions define him as a top expert.

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