Weight Loss Surgery Information for the GP

Bariatric surgery can have positive health outcomes for your patient

Obesity is a metabolic disease which typically has the added complexity of multiple contributing factors. These contributing factors can often be difficult to reverse with diet and exercise alone. We know that obesity tends to present with and contribute to comorbidities such as heart disease, diabetes, hypertension, or depression. Making the process of losing weight even more difficult as the disease progresses. For these patients, bariatric surgery can have life changing health outcomes. Including reversing type 2 diabetes.

It has been shown that patients who undergo bariatric surgery are far likelier to experience sustained weight loss and remission of type 2 diabetes. As well as a reduction in mortality and improvement in many cardiac risk factors.

weight loss surgery information for the gp

Is my patient a suitable candidate?

Suitability for bariatric surgery is generally indicated at a body mass index (BMI) of 35 or greater. However, patients with a BMI of 30 or over who present with comorbidities such as diabetes, heart disease, sleep apnoea, osteoarthritis, or hypertension may also be suitable.

As data on weight loss surgery prevalence and efficacy increases, what determines candidacy for surgery is also evolving. Below are some of the most recent guidelines (2022) from the Australia and New Zealand Metabolic and Obesity Surgery Society (ANZMOSS)/International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO):

  • Metabolic and Bariatric Surgery (MBS) is recommended for individuals with BMI >35 kg/m2, regardless of presence, absence, or severity of comorbidities and for patients with type 2 diabetes and BMI>30 kg/m2.
  • MBS should be considered in individuals with BMI 30 to 34.9 who do not achieve substantial or durable weight loss or comorbidity improvement using nonsurgical methods.
  • Obesity definitions using BMI thresholds do not apply similarly to all populations.
  • Clinical obesity in the Asian population is recognized in individuals with BMI >25 kg/m2.
  • Access to MBS should not be denied solely based on traditional BMI risk zones.
  • Older adults should be considered for MBS after careful assessment of comorbidities and frailty.
  • Carefully selected individuals considered higher risk for general surgery may benefit from MBS.
  • Children/adolescents with a BMI >120% of the 95th percentile and major comorbidity, or a BMI >140% of the 95th percentile should be considered for MBS after evaluation by a multidisciplinary team in a specialty center.
  • MBS is an effective treatment of clinically severe obesity in patients who need other specialty surgery, such as joint arthroplasty, abdominal wall hernia repair, or organ transplantation.

Read the full guidelines here: ASMBS/IFSO Guidelines on Indications for Metabolic and Bariatric Surgery – 2022

If your patient is indicated to be a good candidate for weight loss surgery, there are probably many questions both you and they may have. We hope to outline as many of those questions for you. Should you require further information, you are welcome to reach out to us.

Dr McLeod’s approach to patient care

Dr McLeod takes a modern approach to surgery for obesity. He believes that a complex disease requires a comprehensive, long-term approach. To ensure lasting weight loss, he sees surgery as an important tool to create the necessary anatomical changes that enhance weight loss. This approach is backed by research, which shows that sustained weight loss over the months and years after surgery, is greatly enhanced by supporting the patient in lifestyle changes over the long-term.

He and his team recognise the frontline role General Practitioners have in supporting obese patients with weight loss surgery. Not only in determining suitability and subsequent referral to a bariatric surgeon, but through working with the patient in the days, weeks, and years after surgery. We see your role as a key partnership where we can give the patient every chance at long term health and wellbeing.

Surgical follow-up and care are also provided long after the surgery is over. As well as access to a multi-disciplinary team specialising in dietetics, psychology, and exercise physiology. For G.P.s in Sunshine Coast, Fraser Coast, Brisbane, and surrounding areas, Dr McLeod can also work closely with you as the primary carer of bariatric patients.

Screening Before Surgery

If your patient meets the suitability criteria, nutritional and blood screening will be required to further determine suitability. It is always helpful if they have had preoperative blood testing completed prior to their surgical consultation. Should the patient go ahead with surgery, the results will also allow us to correct any deficits before surgery. As well as provide a baseline for blood and nutrient screening post-surgery. We will send the patient back to you for screening after their consultation should they wish to go ahead, and provided Dr McLeod determines suitability. Or alternatively, you can forward their results before or after sending your referral.

What nutritional and blood screening is required?

Blood Tests

  • Fbe, Elft, Tft
  • Random Blood Glucose
  • Fasting Cholesterol
  • Triglycerides.

Nutritional Screening

  • Iron studies
  • Vitamin B12 (methylmalonic acid optional)
  • Folic acid (RBC folate, homocysteine)
  • 25-vitamin D
  • Vitamin A
  • Vitamin E
  • Zinc
  • Thiamine
  • Parathyroid hormone (optional)

Part of our pre-surgery screening process is that the patient be assessed by an Accredited Practising Dietitian (APD) specialising in bariatric nutrition. The clinic works closely with formidable Sunshine Coast dietitians in this field. They can assess the patient’s nutritional status prior to surgery as part of suitability. The patient will also have access to this dietitian in the weeks and months post-surgery as part of their follow-up plan. We hope it is the beginning of a good relationship with someone who is focused on helping the patient towards making important lifestyle changes for optimal long-term results.

Further tests

Dr McLeod may also require the patient to undergo other tests prior to surgery:

  • Oral glucose tolerance test. This may be required to conclude a DM diagnosis.
  • ECG. In some cases, a cardiologist referral will be required prior to surgery.
  • Pre-op contrast swallow, or an endoscopy.
  • A sleep study.

Surgery preparation and VLED

Dr McLeod will ask the patient to begin a very low energy diet (VLED) around 2–4 weeks before surgery if possible. The VLED assists in reducing the size of the liver, which is often enlarged in obese patients. This reduction helps to reduce complications and ensure a safer and more effective surgery.

Our APD will supervise this diet, which is specified according to the patient’s nutritional requirements. Diabetic patients are monitored closely both for blood glucose and medication. This is to reduce the chance of hypoglycaemia on a VLED.

Post-Operative Care of the Bariatric Patient


Post-operative complications

After surgery, patients can present with complications. Most of these will be monitored and treated by Dr McLeod after surgery. It is important to note that the level of risk a complication poses will differ between surgeries. Some complications are fairly routine following one surgery but can be life-threatening after another.

So how might you decipher this as their General Practitioner? If ever unsure, you are encouraged to call us, Dr McLeod is always happy to discuss any patient concerns over the phone with you.

To give you an idea, here is an outline of what ISN’T normal following common bariatric surgery procedures.

Emergency complications

These patient symptoms will require emergency referral in the days and weeks post-surgery.

  • Pyrexia
  • Tachycardia
  • Abdominal pain
  • Chest pain
  • Repetitive vomiting and epigastric pain (gastric band*, gastric sleeve)
  • Repetitive vomiting and/or dysphagia (gastric bypass)
  • Breathlessness
  • Frank wound infection (gastric band*)
  • Clinical bowel obstruction at any time (gastric bypass)

Abdominal Pain

You should refer abdominal pain for surgical follow up. The urgency is outlined below.

  • Recurring – emergency. In the days or weeks after surgery, any patient with recurrent abdominal pain requires an emergency investigation with Dr McLeod.
  • Intermittent – gastric bypass – urgent referral. Any intermittent abdominal pain in gastric bypass patients is considered an urgent issue. In some cases, it may be an emergency. This is relevant even years after surgery.
  • Intermittent – gastric sleeve. – non-urgent referral. Some intermittent abdominal pain may be routine in the months after surgery. However, this should still be referred for further follow-up.

Nausea, Vomiting or Heartburn

  • Heartburn – urgent referral. In both gastric band* and gastric sleeve patients, heartburn can occur. This complication should be referred for further investigation relatively urgently.
  • Vomiting – gastric band* – urgent referral. Gastric band patients may experience night time coughing and intermittent vomiting, which should be considered an urgent referral.
  • Vomiting – gastric sleeve – non-urgent referral. Gastric sleeve patients may occasionally experience vomiting but a routine investigation by a surgeon is advised.
  • Nausea. – intermittent. Patients may experience nausea in the weeks after surgery. Sometimes eating too fast, too much, or not chewing correctly can cause feelings of nausea. In the early days post-surgery, the patient may be given medication. 
  • Nausea – recurring – urgent referral. Persistent nausea will require further investigation.

*Note: Dr McLeod does not perform gastric band surgery. He does perform gastric band explantation (removal).


While not a complication in and of itself, pregnancy will require referral for additional follow-up care. It is advisable to refer the patient back to Dr McLeod for follow-up care as early in the pregnancy as possible, even if the surgery was performed years earlier. It is advisable for the patient to wait at least 18 months before trying to fall pregnant, to allow for:

  • optimal weight loss provided by anatomical changes.
  • the patient’s vitamin levels to stabilise after the rapid weight loss period to reduce risk of foetal malnutrition.

Poor weight loss and/or weight regain

It is possible for patients to experience poor weight loss. It is more common in the gastric band* patient but can occur with any procedure. Likewise, weight regain in the years after a procedure is also possible. A routine referral for examination is advisable.

*Please note: Dr McLeod doesn’t perform gastric band surgery, but does perform gastric band explantation (removal).

Routine care

Liquid diet

To ensure optimal healing, we ask bariatric patients to follow a liquid diet in the first few weeks after surgery. How rapidly they progress from liquid to solid food will depend on the individual procedure. It will also depend on the patient’s tolerance level. During this time, we emphasise hydration, and adequate intake of protein and nutrients. Both sleeve gastrectomy and gastric bypass patients can take up to 8 weeks to transition to solid food. To ensure adequate healing, it is important not to rush this process.

Medication and supplements

Bariatric patients have specific medication and supplement requirements. They also need to have their medication reviewed periodically.

Medications to avoid.

Patients should avoid nonsteroidal anti-inflammatory drugs.

Medications to monitor and adjust.

It is advised that antihypertensives and lipid medications be adjusted where required but shouldn’t be discontinued without careful consideration. Anti-diabetes medications may also be adjusted. In many cases, diabetes will go into remission.

Supplements required.

The bariatric patient also has new nutritional needs, which they will have for life. The general supplement requirements are:

  • Adult multivitamin and multimineral – containing iron, folic acid, thiamine, vitamin B12. Doses: two daily for sleeve gastrectomy or Roux-en-Y gastric bypass; one daily for adjustable gastric band
  • Citrated calcium – elemental calcium 1200–1500 mg/day
  • Vitamin D – titrates to 25-OH vitamin D levels >30 ng/mL. Typical dose required 3000 IU/day
  • Additional iron and vitamin B12 supplementation as required, based on lab results

Source: RACGP website The Bariatric Surgery Patient.

General Practice follow up

When bariatric patients present for routine checks, the following laboratory assessments are advisable.

  • Full blood count, urea and electrolytes, liver function tests, uric acid, glucose, lipids (every 6–12 months)
  • 25-OH vitamin D,iPTH, calcium, albumin, phosphate, B12, folate, iron studies (annually, more frequently if deficiencies identified)

Source: RACGP website The Bariatric Surgery Patient.

Patients lost to follow up

Research shows that the bariatric patient benefits from long-term follow up. This creates better weight loss outcomes, provides accountability, and provides an opportunity to pre-empt complications.

Those patients who are lost to follow-up care should be encouraged to return to the program. Those who discontinue follow-up care may not see the best results from their surgery, regardless of how well it was performed.

A schedule of three, six, and twelve-month follow-up is ideal. We recommend continued follow-up care for 2-3 years post-surgery, after which time the patient can be discharged back to their GP.

Sometimes the patient cannot be referred to the original surgeon. Here are some instances where it might be appropriate to seek different follow-up care:

  • the patient had surgery where there was no follow-up program in place.
  • they have recently moved to a new area, or
  • they were unhappy with the care they received from their original surgeon.

Follow-up care is important. Patients do best when they are dedicated, and follow-up care helps to ensure enduring commitment to weight loss and health.

bariatric clinic surgical follow up

What’s the next step for patients?

Dr McLeod offers consultations at his rooms in Tewantin, Maroochydore and Gympie. He and his team provide a warm and welcoming environment where patients can discuss their thoughts about surgery. At all times, he is thorough and supportive. The consultation includes details about surgical options, the benefits of surgery, the alternatives to surgery, and of course the risks of surgery. This gives the patient the means to make an informed decision. Patients are encouraged to bring a partner, friend, or support person if they like.

Please feel free to direct your patient to our patient information area, where there is additional inspiration and information about life before and after surgery.

Referral Information

Dr Garth McLeod
Noosa Private Hospital, Buderim Private Hospital

Consulting Rooms

Cooloola Centre, Suite 7 97 Poinciana Ave, Tewantin, QLD 4565
Ph. 07 5353 7100 Fax 07 5353 7104

Also consulting at:

Maroochydore Specialist Centre, Plaza Business Centre, Suite 24, 27 Evans Street, Maroochydore QLD 4558
Gympie Specialist Clinic, 71 Channon St, Gympie, QLD 4570