Bariatric (weight loss) surgery Pokanga whakawhīroki

Weight loss surgery is only for people who are very overweight. The surgery can have more benefits if you have other health conditions, such as:

• type 2 diabetes
• obstructive sleep apnoea (OSA)
• high blood pressure
• gastric reflux
• arthritis
• liver or kidney problems.

There are a limited number of weight loss surgeries done each year in the public health system in Aotearoa New Zealand. You will need to talk with your healthcare provider to see if you meet the criteria to be referred for this surgery in the public system.

There are also private providers offering weight loss surgery in Aotearoa.

Having surgery overseas is not recommended due to the risk of complications and need for ongoing support after an operation. If you have complications from weight loss surgery done overseas you will not be eligible for ACC support.

There are different types of weight loss (bariatric) surgery.

Sleeve gastrectomy

Sleeve gastrectomy reduces the size of your stomach by removing over 90% of it during surgery. The surgery turns the stomach from a 2-litre 'bag' into a 100 ml narrow tube.

Sleeve gastrectomy is a permanent change that cannot be reversed.

Gastric bypass

Gastric bypass involves bypassing much of your stomach and part of your small intestine. This leaves a small pouch for the food to sit in, restricting how much you can eat.

Since it also bypasses part of your small intestine, it means you cannot absorb everything you eat and drink. This means it leads to more weight loss than with sleeve gastrectomy. It also makes it harder to put weight back on.

Gastric bypass is a permanent change that cannot be reversed.

Gastric band

Gastric band surgery involves placing a silicon band around the top of your stomach, reducing its size. This procedure is reversible.

Weight loss is usually slower than with the other types of surgery.

This type of surgery is not recommended in Aotearoa New Zealand as it does not give as good a result as other surgeries. It also has a higher rate of complications.

After surgery your stomach will be smaller. You will feel full after eating small amounts.

• Most people do not feel hungry as often.
• Many surgeries include a malabsorptive component — this means your body cannot absorb everything you eat, which helps you lose more weight.

All surgical procedures have some risks, including from anaesthetics.

Anaesthesia for your surgery

Along with some general, short-term complications that can happen with any surgery, there are other complications that can occur with weight loss surgery, up to several years later.

The complications depend on the type of weight loss surgery you have, but can include:

• stomach contents leaking along a surgical staple line
• ulcers in your small intestine
• internal hernias (internal organs bulging into places they should not)
• vitamin and mineral deficiencies.

The overall complication rate is about 5% (5 in every 100 surgeries). Sometimes complications may mean you need further surgery.

A limited number of people aged between 18 and 60 are eligible for publicly funded weight loss surgery. Publicly funded means the public health system pays for your surgery. Talking with your healthcare provider is the first step to see if you might be eligible.

Criteria for publicly funded surgery vary slightly depending on where you live. Often the criteria include:

• a body mass index (BMI) greater than 40, or greater than 35 with weight-related complications
• issues with being very overweight for longer than 5 years
• failed attempts at weight loss for more than 2 years
• being able to accept the required long-term follow-up and dietary restriction.

Healthy weight BMI calculator

Exclusions to having publicly funded weight loss surgery include:

• being a smoker
• severe heart or lung disease
• active cancer
• liver disease (cirrhosis or portal hypertension)
• Crohn's disease
• an eating disorder.

The limited number of publicly funded surgeries means there is an assessment and selection system. Your healthcare provider will discuss this with you.

Public funding for these surgeries is shared across the regions. For example, if you live in Timaru and are accepted for surgery, you may need to travel elsewhere in the South Island for your surgery.

If you do not want to wait or can afford to pay for your surgery, you can ask your healthcare provider about having it done privately.

Bariatric (weight loss) surgery — Healthpoint

Before weight loss surgery you will meet with a bariatric dietitian. They will discuss your current diet and lifestyle, and changes you can make to look after your health and give you long-lasting results from your surgery. Things they will focus on include:

• eating well
• drinking plenty of fluids
• reasons you put on weight and how you can manage these
• being physically active
• getting enough sleep.

Pre-surgery meal replacement diet

Before your surgery (usually the 3 to 6 weeks before) you will need to go on a very low-calorie meal replacement diet (usually Optifast).

The aim of this diet is to make your liver smaller, which makes the surgery as safe as possible. You will also lose some weight while on the diet. Your dietitian will discuss this with you.

Weight loss surgery will help you to lose weight for about 12 months. After this it is your eating and physical activity routine that keep the weight off for the long term. You can regain weight after having weight loss surgery.

Your dietitian will work with you after surgery to make sure you are meeting all your nutritional requirements as well as learning what your new diet and lifestyle will be. Sessions with your dietitian will cover:

• meal plans to meet your nutritional needs 
• ways of eating and drinking following surgery — adopting good eating habits will help avoid complications such as nutrient deficiencies, throwing up (vomiting), indigestion, food intolerances, constipation and not losing enough weight 
• keeping active and other lifestyle habits to look after your health and wellbeing.

Have 3 meals a day. Try not to snack unless you are physically hungry. Signs include your tummy rumbling or feeling low on energy.

Include a protein-rich food at each meal. Protein-rich foods include:

• meat
• fish and seafood
• eggs
• milk and milk products, or plant-based milks such as soy
• legumes, for example, split peas, beans and lentils
• nuts and seeds.

Focus on your eating

Sit down to eat all meals and remove any distractions — turn off the TV and put phones and other devices away. Eat slowly and chew each mouthful well.

• Aim to drink at least 6 cups of fluid a day. Keep your water bottle with you.
• Drink mostly water and avoid sugary drinks such as fruit juices, milkshakes and fizzy drinks.
• Do not drink with meals or snacks. Leave at least 30 minutes before or after eating.
• Avoid alcohol for at least 9 months after your surgery.

After weight loss surgery you are at risk of getting nutrient deficiencies. You will need to take a multivitamin tablet every day after any type of weight loss surgery, for the rest of your life.

Nutrition supplements after weight loss surgery

Your bariatric dietitian will tell you which multivitamins are best for you to take. Not all multivitamins at the pharmacy or supermarket are suitable for you to take after your surgery. The surgery-specific multivitamin you need to take after your surgery usually costs more than $30 a month.

Taking surgery-specific multivitamins helps to prevent deficiencies. You will still need to have regular blood tests for the rest of your life to check for this. Have these once a year with your healthcare provider.

It is recommended you wait at least 12 months after weight loss surgery before trying to get pregnant.

The weight loss after surgery can increase your chance of getting pregnant so you will need to use appropriate contraception to avoid pregnancy.

If you do get pregnant, your healthcare provider will need to know about your surgery so they can ensure you get the right care. You will need to see a dietitian to make sure you get the nutrients you need during your pregnancy.