Weight Loss Surgery

Gastric Bypass

Everything you need to know about gastric bypass weight loss surgery, from experts in bariatric surgery.

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Over 20 years experience in bariatric surgery
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5 Years Comprehensive After Care Package
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Lifelong psychological and nutritional support
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Over 700 Bypass procedures completed
Image of consultant bariatric surgeon, Mr Rishi Singhal

Gastric Bypass Overview

The Gastric Bypass is a long-established weight loss procedure. Over 30 years of safe and effective weight loss outcomes and significant health benefits. The procedure is carried out laparoscopically via key-hole incisions in the abdomen.

Nationwide specialist clinics and facilities

Lowest published complication rates in the UK

Largest team of surgeons / nurses / clinicians

UK’s most comprehensive aftercare package

What are the Benefits of Having Gastric Bypass Surgery


of type II diabetes are cured (in remission)


will have improvement in cholesterol levels


will have improvement in reflux symptoms


of patients with hypertension reduce or stop medication


of patients with Polycystic ovary syndrome have restored fertility


With Liver Disease will have complete resolution of liver disease


of patients who use a continuous positive airway pressure machine will be able to stop

Turning to the health benefits bypass patients can expect, it’s a long list and the improvements are usually very significant. In many cases people see a complete resolution of their symptoms for the problem they are managing.  Here are some of the more common weight related health problems and the benefit people can expect.**

  • Mobility improves dramatically and joint pain decreases
  • There are improvements in mood and self-esteem, and overall quality of life
  • Perhaps the biggest benefit of all is that people live longer after bypass surgery!

As specialists in weight loss surgery we are familiar with all the health issues associated with obesity. It is also our duty to inform all our patients of the risks and potential complications of gastric bypass surgery, you can view these here. If you have specific health question, please do contact our team and we’ll be pleased to discuss them with you.

Video: How my health improved after weight loss surgery

**Buchwald H et al. Bariatric surgery: a systematic review and meta-analysis. JAMA. 2004 Oct 13;292(14):1724-37.

What is a gastric bypass?

Gastric bypass surgery is the most powerful form of weight loss surgery for people living with obesity. In short, gastric bypass surgery reduces the size of your stomach and redirects the digestive tract. Having a gastric bypass is the best weight loss surgery for patients with a high body mass index (BMI). On average most patients will lose weight of up to 80% of their excess weight after gastric bypass surgery. Alongside the weight loss, the gastric bypass can help reverse serious weight-related health conditions such as type 2 diabetes and PCOS. 

The Gastric Bypass Helps People Lose Weight By

  • The gastric bypass reduces the capacity of the stomach from full-sized into a small pouch, meaning you don’t need to eat as much to feel full
  • The pouch gets connected to the small intestine, bypassing the rest of your stomach and fewer calories are then absorbed.

UK’s most comprehensive aftercare package

The importance of great aftercare is often underestimated when it comes to gastric bypass. Most patients enjoy excellent weight loss in the first year or two but some weight regain is quite common after a few years. This can be reduced by adopting the correct dietary and exercise habits in the first couple of years after surgery. 

Healthier Weight gastric bypass patients benefit from 5 years post-operative care including medical monitoring via regular follow-ups with our specialist bariatric nurses and surgeon reviews if required

Gastric Bypass Procedure

The procedure is carried out laparascopically via key-hole incisions in the abdomen.

Dedicated Support

Our range of nutritionists, Health Coaches and support team are here to help every step of the way                  

Weight Loss Tools

Videos and live classes on diet, fitness, retraining behaviours, body composition scales and activity tracker.  

Gastric Bypass Operation

The simplest way to describe bypass surgery is to say that the stomach and bowel are ‘re-plumbed’ so that the food you eat goes into a reduced stomach before passing directly into the bowel a little further down the bowel than was the case before. The bypass works in two ways. Firstly, by reducing the size of the stomach and so restricting the amount of food that can be eaten. We usually reduce the stomach’s capacity by as much as 90-95%. On this page, we give a technical breakdown of how the procedure is done.

Am I eligible for the Gastric Bypass?

The ideal candidates for gastric bypass surgery are those who have a body mass index (BMI) of 40 or higher, or a BMI of 35 or higher with significant obesity-related health conditions like type 2 diabetes, high blood pressure, or sleep apnea. These individuals should have also made sincere efforts to lose weight through conventional methods such as diet and exercise, without achieving sustainable results. 

In the United Kingdom, the National Health Service (NHS) provides gastric bypass surgery for eligible individuals. To access this procedure through the NHS, patients typically need a referral from their primary care physician. The referral is usually made to a specialist bariatric service, where further assessments and evaluations are conducted to determine the appropriateness of the surgery. The decision to offer gastric bypass surgery on the NHS is based on various factors, including the patient’s BMI, their obesity-related health conditions, and the impact of these conditions on their overall well-being. The waiting times for surgery can vary depending on the local NHS policies and resource availability.

At Healthier Weight, we specialise in bariatrics. We offer gastric bypass surgery for individuals seeking a dedicated and personalised approach to their weight loss journey. Our criteria for eligibility focus primarily on a BMI of 35 or higher, with no upper BMI limit, as we specialise exclusively in weight loss procedures. We understand that obesity affects individuals differently, and our team of experienced surgeons, dieticians, and support staff are dedicated to evaluating your unique circumstances. We prioritise your individual goals, health conditions, readiness for the procedure, and long-term commitment to ensure the best outcomes.

How Much Weight Will I Lose with the Gastric Bypass

Of course, the main benefit people are seeking when they have bypass surgery is to lose weight. There are other significant benefits, however, especially where improvements in health are concerned. Those people who are managing health problems associated with their weight can expect significant improvements after the bypass.

Typically, we expect gastric bypass patients to lose 60-70% of their excess weight over a 2-year period, and most of this weight is lost in the first year after surgery*. You will see from our case studies that some people lose all their excess weight. 

To compensate there will be some who lose a little less. For this reason, 70-80% is a reasonable expectation. Weight loss results will differ from person to person and your results, especially in the long term, will depend on how well you are able to adapt your lifestyle and eating habits. Our bariatric aftercare team is vital to helping you learn and embed the skills needed to maximise and maintain your weight loss (see before and after photos and stories from gastric bypass patients here).

Weight loss example

  • A 5ft 6in person weighing 17st (240lbs / 109kgs) has an ideal weight of about 11st (154lbs / 70kgs)
  • They are carrying excess weight therefore of 86lbs (240lbs actual weight minus 154lbs ideal weight)
  • 70% of 86lbs is around 60lbs
  • So, this person could expect to lose (on average) about 60lbs (27kgs).

Scientific evidence suggests that most gastric bypass patients who comply with the follow-up requirements, including nutritional recommendations, do very well, and see great long-term results*. Moreover, compared with obese individuals who have not had surgery, gastric bypass patients have a much lower risk of premature death and disability.

*JAMA. 2012 Jan 4;307(1):56-65. doi: 10.1001/jama.2011.1914. Bariatric surgery and long-term cardiovascular events

Gastric Bypass success stories

Nik’s Transformation

Lost 16 Stone

“The gastric bypass was the only way to get rid of the demons”                                                                        

Georgina’s Transformation

Lost 7 Stone

“The mutual support both in that group and in the Healthier Weight aftercare team has been amazing”

Kerry’s Transformation

Lost 8 Stone

“Healthier Weight was the only provider that made her feel comfortable”.

Gastric Bypass cost and finance

At Healthier Weight, we provide you with a fixed-price gastric bypass package. You have certainty of the cost of your treatment, including aftercare, blood tests and any treatment required in relation to a complication arising from your procedure. The fixed price of your gastric bypass will vary depending on several factors including your location, the type of gastric bypass (primary or revision) and any special treatment requirements that are identified in the pre-operative period.

In order to help as many people as possible gain access to our services, we have developed a number of monthly payment plans tailored to the needs of our patients.

Clinics offering the Gastric Bypass

Healthier Weight Starter Kit

Gastric Bypass common FAQs

This depends upon what you do for a living, but if you have a sedentary occupation you can generally expect to be back at work about 2 weeks after gastric bypass, after which time the wounds should have healed and you will be feeling more comfortable. If you have a physically demanding job involving lifting etc, you may need a little longer. The bowel and stomach inside your abdomen will be healed in around 6-8 weeks, so during this period it is important that you follow the nutritional guidelines as closely as you can.

Your long term success with your procedure is dependent on high quality aftercare. Anyone who has had weight loss surgery will tell you this is crucial. All too frequently, overseas surgery packages have no aftercare.

In the UK surgeon outcomes are monitored closely. There is a duty of candour and transparency. In many overseas countries the same standards do not apply.

We have seen many botched procedures from overseas that come with limited aftercare and warranties. You won’t receive any support from any serious problems that arise post-op, and you will ultimately go onto the NHS waiting list for your procedure to be put right.

Generally there is minimal scarring with a gastric bypass. The operating ports are placed in the abdomen through 5 narrow (0.5 cm) incisions which are sutured and/or glued and will normally heal in about 10-14 days. The scars should fade gradually. Some individuals have a greater tendency to form keloid which may result in thicker and more prominent scars.

You may eat most foods that don’t cause you discomfort. However, because you can only  eat small amounts, it is important to include foods rich in protein but low in fat and sugar. We encourage you to eat vegetables, fruit, wholegrains, lean meat and fish. You will be provided with detailed nutritional information following your gastric bypass surgery.

Image of consultant bariatric surgeon, Mr Rishi Singhal

All content on this page is reviewed by a multi-disciplinary team led by Prof Rishi Singhal.

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