Everything you need to know about gastric bypass and its impact on losing excess weight.

Topic: Gastric bypass Canberra

The team at Capital Metabolic Clinic offers ongoing support, before, during and after gastric bypass surgery. 1 year post-surgery, you may have lost about 70% to 100% of your excess weight but it requires changing lifestyle habits and adopting sustainable health practices. Are you ready for change?

Quick facts about gastric bypass

A gastric bypass is a surgical weight loss procedure and it consists of creating a new pouch from your stomach and attaching it to your small bowel.
To be eligible for bariatric surgery, you need to have a BMI higher than 35, or a BMI higher than 30 with more than one associated metabolic condition.
You will be on a post-operative diet, and it will take up to 4 to 6 weeks before you can eat solids again. You will eat much smaller portions, spread across more frequent small meals.
1 year after surgery, you may have lost about 70% to 100% of your excess weight, depending on the type of gastric bypass.

Gastric bypass surgery is a safe and accepted method of weight loss surgery. The staff at Capital Metabolic Clinic are experienced in managing and supporting patients who have undergone primary or revision gastric bypass surgery. I want my patients to have the best available care after weight loss surgery.

Ready for change?

Contact our friendly team at
(02) 6210 1070

Why is gastric bypass not the commonest type of weight loss surgery?

The sleeve gastrectomy accounts for 70 to 80% of all weight loss procedures in Australia as reported by the Bariatric Surgery Registry in 2020. In contrast, gastric bypass surgeries are performed in 15 to 20% of cases.

Bariatric surgery as a discipline is relatively new to Australia. Training for bariatric surgery is provided by centers accredited by ANZMOSS, which provide the basis for bariatric practice that is safe and holistic.

I have been very fortunate to have trained in an ANZMOSS accredited, highvolume, bariatric centre for two years and am comfortable performing gastric bypass and revision procedures. When discussing your surgical options, we will consider the best options based on current evidence and guidelines.

Large volume studies have demonstrated that gastric bypass has better long-term weight loss outcomes than the sleeve gastrectomy, and research continues into the mechanisms and science behind this.

A vast effect on metabolic hormones is modulated by the gastric bypass, which has been shown to persist in blood test results from patients who are ten years post procedure.

This enduring metabolic shift is not seen in sleeve gastrectomy patients past 18 months, which is why diabetes remission in these patients is contingent on t weight loss. Greater metabolic effects independent of weight loss are seen in metabolicconditions in gastric bypass patients.

Types of bypasses: single anastomosis bypass

In a single anastomosis bypass, a small gastric pouch is fashioned with staplers and attached to the small bowel, bypassing a length of about 150cm from the remnant stomach. The gastric pouch confers restriction of intake and the bypassed small bowel changes the hormonal response to food and the metabolic response to weight loss. These mechanisms are a powerful method of weight loss.

Types of bypasses: Roux-en-y bypass

In the Roux-en-y gastric bypass, the bypassed length is similar but the bowel is divided and reattached to form a roux loup to disperse pressure in the digestive system. The roux loup was imagined by surgeons performing gastric cancer surgery whose patients subsequently developed severe gastric reflux. It is therefore a very suitable and safe operation for gastric sleeve patients requiring surgery because they have serious reflux problems or if revision surgery is needed.

How much weight will I lose with a gastric bypass?

When you have a single anastomosis bypass, we expect you to lose 80-90% of excess weight 1 year after your surgery. For a roux-en-y gastric bypass, we typically see 70-80% of excess weight loss 1 year post-surgery. On average, 10 years after surgery, the excess weight loss is 60-80%.

Am I a candidate?

If you have a BMI over 30, with a medical illness related to excess weight, you are a candidate for bariatric surgery. If your BMI is higher than 35, you are also eligible for weight loss surgery. These BMI limits have recently been changed by the ASMBS (American Society for Metabolic and Bariatric Surgery) in 2022.

Whether you will have a gastric sleeve surgery or a gastric bypass will depend on your personal choices, medical conditions and objectives.

The multi-disciplinary team collectively makes the recommendation for surgery based on medical, personal, and psychological factors to ensure an sustainable and meaningful result.

We believe that you should be empowered to make your own decision about your surgery and know that patient safety is our priority. Our team will take a holistic approach and guide you through the process of education and assessment to match the appropriate surgery to your medical profile.

My BMI is between 30 and 35. What medical conditions are considered in order to be eligible for weight loss surgery?

Are there any conditions that could be a reason not to have weight loss surgery?

For your own safety, our team will screen you for any potential barriers or contraindications for surgery. The following are some conditions that need to be resolved prior to gastric bypass surgery.

If you have unresolved or untreated eating disorders or psychological disorders.
If you are a smoker or user of recreational drugs.
If you have uncontrolled medical conditions.

In these instances, we would offer our patients optimisation of conditions that are barriers to surgery, to allow access to surgery when appropriate. A consideration to start neoadjuvant or complimentary medical therapies or interventions like a gastric balloon are reasonable options of bridging patients to surgery.

I am eligible from a BMI perspective. What’s next?

The weight loss surgeon will first assess you after which you will meet the bariatrician, the psychologist and the dietitian. Whether you are a candidate for bariatric surgery depends on multiple factors, not just your BMI.

Psychological preparation for surgery helps you maximise the benefits of the intervention that you choose, assisting you to adjust well, and find a long term sustainable relationship with food and your body.

Once you have been consented and surgery is booked, our dietitians will guide you througha Very Low Energy Diet, abbreviated as VLED. It is a pre-operative diet based on calorie restriction to enable safe manipulation of your liver during surgery. It often includes dietary products such as soups, shakes and protein bars. Everyone is different, and our dietitians will ensure you are getting an individualised amount of protein and calories before surgery.

How long will I be on the pre-operative diet?

You start your VLED diet two to three weeks before your surgery. Our dietitians are very experienced in supporting patients through this challenging time and will work with you to make it feasible.

How can I best prepare for my surgery?

We encourage you to be active. This can be as simple as walking for half an hour a day. If it is already one of your daily habits, you may want to add a variety of strength training exercises to your activities. Some examples of how our practice dietitians can help are:

Patients with arthritis are encouraged to do hydrotherapy-based exercises with our exercise physiologists.
Some patients may need assistance in changing their diet and lifestyle prior to surgery. Small changes like learning to read nutritional labels, focusing on healthier meals and fluid intake form the basis of success for the future. Keeping a food diary may be useful too, to keep track of your food intake and as an aid to discuss your progress.

Ongoing support: before, during and after surgery

You may have read stories about other people who have had weight loss surgery. Or your friends may have discussed the journey that it has been for them. Having access to ongoing support, before, during and after surgery is pivotal for your healing and for the best outcome.

Capital Metabolic Clinic supports you throughout the journey. Our anaesthetists and surgeon have adopted best practices in providing an enhanced recovery-after-surgery program. This program is called Enhanced Recovery After Bariatric Surgery (ERABS) . It is a standardised perioperative protocol of medications and post-operative instructions to help you recover from major surgery as quickly as possible.

ERABS encompasses all aspects of the bariatric patient journey. It improves patient outcomes, reduces complications and increases patient satisfaction.

Capital Metabolic Clinic is the only practice in Canberra that offers the program in the private hospital setting. Suitable patients can participate in the ERABS program and can be discharged safely within 24 hours after surgery. This has been shown to be the standard of care for all patients undergoing major surgery.

The enhanced recovery after bariatric surgery protocol is scientifically published and peer-reviewed by other health professionals who are part of the ERAS society.

You will receive handouts and prescriptions to participate in this protocol, and be able to attend education sessions with our pharmacists. The protocol is continued in the hospital from when you are admitted for surgery to the time of discharge.

What to expect on the day of my surgery?

Before we dive into this topic, let’s start with what happens in the week your surgery is scheduled. The hospital will ring you and do a pre-admission check. If you are deemed suitable, you will pick up your ERABS pack at the pharmacy to help you prepare for surgery. This pack includes pre-packaged medications and preventative strategies to reduce complications and improve your recovery after the procedure.

Medications are taken the day before surgery in anticipation of surgery, including a carbohydrate loading drink. On the day of your surgery, you will be checked into the holding area and the pre-admission nurse will give you the remainder of your preparatory medications and second carbohydrate loading drink. The nurse will also make sure that your documentation, your fasting status, health history and allergy status are all up-to-date.

When your scheduled surgery time approaches, you will be brought to the anaesthetic bay where the anaesthetic nurse will perform a standard list of checks and the anaesthetist will reassess you and prepare you for surgery. You will be given a full anaesthetic, positioned, prepared and draped for surgery. The bariatric surgeon will then make 5 small incisions to allow for laparoscopic or keyhole surgery.

When the gastric bypass surgery is completed, the wounds are closed, your abdomen is cleaned and dressings are applied. The anaesthetist administers medications for when you wake up in the recovery bay. You will be cared for by recovery nurses who are very experienced in providing appropriate medication and ensuring a safe recovery from anaesthesia. From the recovery room, you will be transferred to a high dependency unit for ongoing care, prior to discharge.

Most of our gastric bypass patients leave the hospital within 24 to 48 hours. If you have had complex or revision surgery, you may need to stay in the hospital for up to 72 hours.

Do’s and don’ts after surgery?

Driving: Once you are pain-free, off all pain medication and able to take evasive action in the car.
Shower: Immediately after surgery. The dressings are made of waterproof glue. In the first 6 weeks, you will not be taking any baths.
Low-impact exercise: from 2 to 4 weeks after surgery. (Walking is an example of low-impact exercise).
Higher impact activities: after week 6. Swimming may be started from week 6 and our exercise physiologists conduct weekly aqua classes which you may choose to attend. Physical activity is very important for cardiovascular health, maintenance of weight loss, bone health and mental well-being. Establishing better relationships with friends and family, centred away from eating and drinking, may also be helpful.
Work: Most patients are able to return to work after 2-3 weeks at reduced capacity or able to work from home. Almost all patients are back at work full-time by week 4.
Lifestyle: A re-established relationship with food for nutrition and enjoyment is very important. Focusing on health and nutritious food requires re-education to develop healthy habits like meal preparation, reading food labels and making better food choices when eating out or in the home.
Alcohol: It is not recommended to have alcohol in the first year after bariatric surgery.
- increased transit times mean that alcohol is processed differently and possibly more quickly,
- alcohol contains empty calories,
- alcohol is a gastric and small bowel mucosa irritant that can affect healing,
- alcohol can cause liver inflammation/damage and add to the burden of weight loss. In some instances, the liver damage may not be reversible.
Speak to your bariatric physician or surgeon you would choose to have alcohol.

Once you have had weight loss surgery, you will need to take daily multivitamins for the rest of your life.

We can help you find a long term dietary pattern that is sustainable, enjoyable and suits your body and health goals. Contrary to popular belief, weight loss is not about restriction or strict diets, it is about eating in abundance a wide variety of fresh whole foods from all of the core food groups

Additional Calcium and Vitamin D supplementation are often required as bariatric surgery reduces the reabsorption of Calcium in the kidneys. In patients with osteoporosis, osteopaenia or menopause, bone health is especially important to maintain.

What are the most common side effects after gastric bypass surgery?

Dumping syndrome, diarrhoea, abdominal cramps and constipation are the most common side effects after gastric bypass surgery. We will talk about these extensively during your consultation.

Risks and complications after gastric bypass?

Risks with general laparoscopic surgery include: bleeding, infection, developing a collection of fluid, sepsis, gas pain and adhesions. Specific risks with gastric bypass include: malnutrition, anastomotic or bowel leak, adhesions, stenosis of joins or anastomoses, internal hernia, intussusception or telescoping of the small bowel and marginal ulcers.

When is gastric sleeve surgery a better choice?

A gastric sleeve is an option for patients who need a two-step procedure due to technical difficulties or a higher BMI. Gastric sleeve may also be more appropriate in patients with lower BMI, but this decision needs to be made between surgeon and patient.

Will the weight loss last after gastric bypass surgery?

Weight loss with gastric bypass surgery is superior to gastric sleeve surgery. It is due in part to the long-term hormonal effects that can modulate cellular metabolism and endocrine function. Generally patients keep at least half the excess weight lost at ten years post procedure.

Diet after surgery

After surgery, your diet will look like this:

Week 1-2: fluid diet phase
Week 3-4: puree diet phase
Week 5-8: soft diet phase
After week 8: diet as tolerated.

Our dietitian will explain this new regime in the weeks or months before your surgery, giving you time to begin changing your routines. Frequent small meals are important. In the first three to six months, the typical volumes you would eat are ¼ to ½ cup. Our dietitians are here to support you as you transition through the different diet phases.

So, are you ready for a change?

Making a decision for surgery is not taking the easy way out of managing obesity. Gastric bypass surgery is very effective and confers a large amount of excess weight loss. Despite being a very effective treatment option, our patients need to be ready to make necessary changes in order to succeed in the long-term.

There needs to be a willingness to change your lifestyle habits and adopt a healthy lifestyle. Capitalising on the rapid weight loss in the early postoperative period is the best advice I can offer you. Obesity surgery outcomes are maintained by a healthy lifestyle which can change your health and life.

The magnitude of weight loss and effects on weight-related medical issues is unmatched by conventional and medical weight loss.

So, are you ready for a change? The team at Capital Metabolic Clinic looks forward to supporting you on your weight loss journey.

Ready for change?

Contact our friendly team at
(02) 6210 1070