A New Zealand guide for patients in Dunedin, Invercargill & Queenstown
By Mark Grant FRACS | Southern Weight Loss
Quick Answer
For people in New Zealand considering weight loss treatment:
- Gastric sleeve often suits people wanting strong weight loss with a simpler operation.
- Gastric bypass often suits people with reflux, diabetes, or those needing greater long-term weight loss.
- Wegovy may suit people wanting a non-surgical option with meaningful weight loss and appetite control.
- Mounjaro may suit people wanting stronger medication-based weight loss, especially with insulin resistance or diabetes.
The best option depends on: BMI, reflux symptoms, diabetes, food noise / hunger, previous regain, budget, preference for surgery vs medication, and long-term goals.
At Southern Weight Loss, Mark Grant helps patients across Dunedin, Invercargill, Queenstown, Otago and Southland choose the right pathway with expert local follow-up.
Quick Decision Table
| If you want… | Often best option |
|---|---|
| Strongest long-term weight loss | Gastric bypass |
| Avoid surgery | Wegovy / Mounjaro |
| Significant reflux relief | Gastric bypass |
| Simpler surgery | Gastric sleeve |
| Strong appetite suppression | Mounjaro |
| Lower upfront cost | Medication |
| One-off treatment pathway | Surgery |
| Diabetes improvement | Bypass / Mounjaro |
Why This Choice Matters
Many patients ask:
- Should I get sleeve or Wegovy?
- Is Mounjaro better than surgery?
- What’s best for reflux?
- Which gives better long-term results?
- What should I choose in New Zealand?
There is no single “best” treatment. The right treatment is the one that matches your biology, health conditions, lifestyle and long-term plan.
Option 1: Gastric Sleeve
What is it?
A gastric sleeve removes part of the stomach, reducing capacity and lowering hunger hormones such as ghrelin.
Often suits people who:
- Want strong weight loss
- Prefer a simpler operation
- Have BMI 35+
- Struggle with portions and appetite
- Want to avoid lifelong injections
Typical benefits:
- Significant weight loss
- Reduced hunger
- Improvement in blood pressure and diabetes
- No intestinal bypass
Potential downsides:
- Can worsen reflux in some patients
- Usually, less weight loss than bypass on average
- Irreversible
My clinical view
Mark Grant often recommends sleeve for suitable patients wanting a powerful but simpler surgical option without significant reflux.
Option 2: Gastric Bypass
What is it?
A gastric bypass creates a small stomach pouch and reroutes part of the small intestine.
Often suits people who:
- Have reflux / GORD
- Have type 2 diabetes
- Need stronger long-term weight loss
- Have severe obesity
- Need revision after sleeve
Typical benefits:
- Excellent weight loss outcomes
- Often best surgical option for reflux
- Strong diabetes improvement
- Powerful appetite changes
Potential downsides:
- More complex surgery
- Lifelong vitamin supplementation important
- Small risk of ulcers / internal hernia depending on type
My clinical view
When reflux is significant, Mark Grant often favours bypass over sleeve.
Option 3: Wegovy
What is it?
A once-weekly GLP-1 medication that reduces hunger and increases fullness.
Often suits people who:
- Want non-surgical treatment
- Need moderate to significant weight loss
- Have food noise / cravings
- Prefer to avoid surgery initially
Typical benefits:
- Effective appetite control
- Improves metabolic health
- Non-surgical
- Can be started quickly
Potential downsides:
- Ongoing monthly cost
- GI side effects possible
- Weight regain common if stopped
Option 4: Mounjaro
What is it?
A once-weekly dual GIP/GLP-1 medication that often produces greater weight loss than GLP-1 alone.
Often suits people who:
- Need stronger medication response
- Have insulin resistance
- Have diabetes
- Higher BMI
- Want to avoid surgery initially
Typical benefits:
- Often strongest medication weight loss
- Strong appetite suppression
- Excellent glucose benefits
Potential downsides:
- Ongoing cost
- GI side effects possible
- Long-term treatment usually needed
Which Option Gives the Most Weight Loss?
| Treatment | Approx Total Body Weight Loss |
|---|---|
| Wegovy | 10–18% |
| Mounjaro | 15–22% |
| Gastric Sleeve | 25–30% |
| Gastric Bypass | 30–35% |
Individual results vary.
Which Option is Best for Reflux?
Often strongest choice: Gastric bypass.
Sometimes less ideal: Gastric sleeve if significant reflux already exists.
This is one of the most important decision factors.
Which Option is Best for Diabetes?
Strong options include:
- Gastric bypass
- Mounjaro
- Wegovy
For many patients with obesity and diabetes, these can be transformative.
Which Option is Best for Food Noise & Hunger?
Many patients experience strong appetite improvement with:
- Mounjaro
- Wegovy
- Gastric bypass
- Gastric sleeve
Some patients describe this as food becoming “quieter”.
Which Option Costs Less Long-Term in NZ?
Medication: Lower upfront cost, but ongoing monthly cost.
Surgery: Higher upfront cost, but often one-off treatment with long-term value.
For some patients, several years of medication costs may approach surgery costs.
New Zealand Specific Considerations
Patients in Dunedin, Invercargill, Queenstown and Southland often ask about access.
Important NZ factors:
- Most medications are privately funded
- Private surgery pathways available
- Self-referrals accepted
- GP referrals accepted
- Local follow-up matters for long-term success
- Travel to major centres is not always necessary
Southern Weight Loss provides local expert care in the lower South Island.
Can I Start with Medication Then Have Surgery Later?
Yes.
Many patients choose:
- Medication first, surgery later
- Surgery first, medication later for maintenance
- Sleeve then revision bypass if needed
The best plan often changes over time.
Why Southern Weight Loss is Different
Many clinics offer only medication or only surgery.
Southern Weight Loss offers:
- Gastric sleeve
- Gastric bypass
- Wegovy guidance
- Mounjaro guidance
- Revision surgery
- Food noise expertise
- Long-term follow-up
- Local specialist care
Expert care provided locally. Dunedin | Invercargill | Queenstown
Frequently Asked Questions
Is surgery better than Wegovy?
Not always. Surgery often gives greater durable weight loss, but Wegovy suits many patients wanting non-surgical treatment.
Is Mounjaro better than gastric sleeve?
They are different tools. Mounjaro may suit patients avoiding surgery. Sleeve often gives stronger durable loss.
Is Mounjaro stronger than Wegovy?
Often yes for average weight loss.
Is gastric bypass better than sleeve?
For reflux or diabetes, often yes. For others, sleeve is excellent.
Which is safest: sleeve, bypass or injections?
Each has risks and benefits. Suitability depends on the individual.
What gives the fastest weight loss in NZ?
Results vary, but surgery and Mounjaro often produce the greatest early changes.
Can I self-refer?
Yes. Southern Weight Loss accepts self-referrals and GP referrals.
Book a Consultation
If you are deciding between gastric sleeve, gastric bypass, Wegovy or Mounjaro, we can help you choose the right path.
Southern Weight Loss | Mark Grant FRACS | Dunedin | Invercargill | Queenstown | Otago | Southland