Weight Loss Surgery · Australia

Bariatric surgery —
explained honestly.

Weight loss surgery remains the most effective long-term intervention for significant obesity. This page explains what each procedure does, what the outcomes look like, what comes after — and the nutritional preparation that determines whether the result is good or exceptional.

Compare procedures → Bariatric nutrition support

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Calm, modern private hospital setting — consultation room, bright and reassuring.

Who qualifies?

Candidacy for bariatric surgery

Bariatric surgery in Australia is generally considered for patients who meet established clinical criteria. These are reviewed and applied individually by the treating surgical team.

Generally meets criteria

BMI ≥ 40 kg/m² regardless of other conditions
BMI ≥ 35 kg/m² with at least one significant comorbidity (Type 2 diabetes, hypertension, sleep apnoea, joint disease, fatty liver)
Failed sustained weight loss with non-surgical approaches
Medically fit for laparoscopic surgery under general anaesthesia
Psychologically assessed as suitable (mandatory pre-operative assessment)
Committed to lifelong dietary change and follow-up

May not meet criteria or requires additional assessment

Active or recently treated malignancy
Significant uncontrolled psychiatric illness
Severe oesophageal or gastric disease
Active substance dependence
Inability to comply with post-operative follow-up requirements

The pre-operative journey

Referral & GP consultation

A referral from your GP to a bariatric surgical team is the starting point. Your GP will also facilitate pre-operative blood work, screening investigations and specialist referrals for comorbidities.

Multi-disciplinary assessment

Bariatric surgery requires input from a surgeon, physician or endocrinologist, dietitian and psychologist before proceeding. This team assesses your suitability, your preparation and your realistic expectations.

Nutritional pre-hab (essential)

The liver reduction diet — typically a low-calorie, low-carbohydrate programme for 2–6 weeks before surgery — shrinks the liver to improve laparoscopic access and reduce operative risk. Amy Kellner APD provides the full pre-operative nutrition programme.

Surgery & hospital stay

Laparoscopic bariatric procedures typically involve 1–3 nights in hospital. Return to light activity in 1–2 weeks; full activity in 4–6 weeks.

Lifelong follow-up

Annual blood work, ongoing dietitian review and surgical follow-up are lifelong requirements after bariatric surgery — not optional. Nutritional deficiencies are common and require active monitoring and supplementation.

The operations compared

Bariatric procedures — what each one does

The three primary bariatric procedures differ in mechanism, efficacy, reversibility and nutritional impact. Understanding these differences helps patients make an informed choice with their surgical team.

Anatomical comparison diagram showing gastric sleeve, Roux-en-Y bypass and gastric band procedures

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Schematic anatomical comparison of the three primary bariatric procedures — gastric sleeve, Roux-en-Y gastric bypass and adjustable gastric band. Diagram shows mechanism of restriction and (for bypass) malabsorption. Clinical illustration — myweightlossjourney.com.au.

Procedure	Mechanism	Expected excess weight loss	Hospital stay	Reversible?	Key nutritional impact
Laparoscopic Sleeve Gastrectomy	Restriction only — ~80% of stomach removed; stomach reduced to a tube/sleeve. Some hormonal effect (ghrelin reduction).	60–70% EWL at 12 months (~20% total body weight)	1–2 nights	No	Reduced intake capacity. Protein first. Vitamin B12, iron, Vitamin D supplementation lifelong.
Roux-en-Y Gastric Bypass	Restriction + malabsorption. Small gastric pouch created; small intestine rerouted to bypass stomach and duodenum. Significant hormonal changes.	70–80% EWL at 12 months (~28% total body weight)	2–3 nights	Technically yes, rarely done	Significant malabsorption. Mandatory lifelong micronutrient supplementation (iron, B12, folate, calcium, Vitamin D). Dumping syndrome risk. Protein priority always.
Adjustable Gastric Band	Restriction only — silicone band around upper stomach creates small pouch. Band adjustable via port under skin. No stomach removed.	40–50% EWL at 12 months	Day surgery or 1 night	Yes — fully reversible	Restriction in volume. Nutritional impact less than sleeve or bypass. Regular dietary follow-up still required.

EWL = Excess Weight Loss. Results vary significantly between individuals based on pre-operative BMI, dietary adherence, physical activity and follow-up compliance. Figures from published Australian bariatric surgery outcome data.

Visual comparison

How each bariatric procedure changes the stomach

A simplified visual guide to what each operation does anatomically. Not to scale — for patient education only.

Option 1

Gastric Sleeve

~80% of stomach removed

✓No rerouting of intestine
✓60–70% excess weight loss
→Irreversible

Option 2 · Highest efficacy

Gastric Bypass

Restriction + malabsorption

✓70–80% excess weight loss
✓Strong hormonal effect
→Lifelong supplementation needed

Option 3

Gastric Band

Adjustable restriction only

✓Fully reversible
→40–50% excess weight loss
→Regular adjustments needed

The part most programs don't plan for

What happens after the weight comes off?

The bariatric surgery pathway is well-established. The nutritional monitoring is well-established. What is frequently under-discussed — until patients are living it — is what significant weight loss does to the body's skin.

Patients who lose 50, 60, 70 or 80 kilograms following bariatric surgery almost universally develop significant skin excess — across the abdomen, flanks, arms, thighs and breasts. This skin does not retract regardless of how much muscle is built or how diligently scar care protocols are followed. The stretched, permanently altered skin fibres cannot recover structurally.

Body contouring surgery — typically beginning 12–18 months after bariatric surgery, once weight is stable and nutritional status is optimised — is how patients complete what the bariatric procedure began. It is the final chapter of the transformation.

Explore body contouring surgery →

Timing — when can I have body contouring?

Minimum 12 months after bariatric surgery; 18 months is preferred. Weight must be stable — genuinely plateau'd, not still declining. Nutritional status assessed and optimised. BMI ideally below 33. All of this is assessed at your body contouring consultation with Dr Kumar.

Nutrition before body contouring

Post-bariatric patients frequently have nutritional deficiencies — particularly iron, B12, Vitamin D, zinc and albumin — that must be identified and corrected before body contouring surgery. Amy Kellner APD's pre-surgical protocol is designed specifically for post-bariatric patients approaching body contouring.

Staging after bariatric surgery

Post-bariatric patients typically have the most extensive skin excess of any body contouring population — requiring more areas and sometimes more stages than patients who have lost weight through other pathways. Dr Kumar develops an individualised staging plan at consultation based on your priorities and anatomy.

Bariatric nutrition support → Book with Dr Kumar

Bariatric surgery —explained honestly.