Gastric banding, gastric sleeve and gastric bypass explained

by | Diet and Weightloss

There are several different types of bariatric surgery available in Australia (see below). The type of surgery that is most suitable for you will depend on factors such as your body mass index (BMI), other health problems, your current eating patterns/habits and the risks associated with each type of surgery.

Gastric banding

Laparoscopic adjustable gastric banding (LAGB), commonly referred to as ‘lap band’ surgery or ‘lap banding’, is done via laparoscopy (keyhole surgery).

A silicone band with an inflatable inner balloon is placed around the upper part of the stomach, which reduces the capacity of the stomach.

How does gastric banding work?

The band ensures you feel full after you have eaten only a small amount of food. The tightness of the gastric band can be adjusted by means of injecting fluid into or out of it through an access device, located under the skin of the abdomen. This adjustment is a simple procedure and can be done on an outpatient basis.

Gastric banding does not affect the digestive processes of the body, so food is still absorbed normally. After gastric banding, you can eat 3 balanced meals a day, although the portions will be smaller than they were before the operation. People need to eat slowly and each mouthful needs to be small and chewed properly before swallowing. You should not drink liquids with meals. It is very important for people who have had gastric banding to continue to follow dietary advice and an exercise programme.

Regular follow-up with your doctor and other health professionals is needed after the procedure, to ensure its effectiveness. The band is designed to remain in place permanently, but can be removed if necessary.

Effectiveness of gastric banding

Gastric banding has been shown to be very effective for weight loss. Research shows that with a good follow-up programme, it can be associated with a decrease of up to 60 per cent of excess weight after 2 years. (Weight is generally lost at a rate of 0.5 to 1 kg per week.)

Complications and side effects of gastric banding

Improvements in surgical techniques have meant complications following lap band surgery are now uncommon. There is a slight risk of the band slipping down the stomach, and very occasionally eroding into the stomach. About 5 per cent of people need a further laparoscopy to manage complications such as these.

Side effects include vomiting and regurgitation if you eat too much or too quickly. Heartburn and other symptoms of gastro-oesophageal reflux can also occur.

Gastric sleeve surgery

Gastric sleeve surgery (also called vertical sleeve gastrectomy) involves permanently removing most of the stomach, so that instead of having a 2 litre capacity, it can only hold about 200 mL. This procedure is performed via laparoscopy (keyhole surgery).

Reducing the volume of the stomach means you can’t eat as much and feel full much faster. Also, removing the part of the stomach that releases the hormone responsible for feeling hungry (ghrelin), means that people feel less hungry and eat less. This procedure is especially helpful for those who have a history of eating very large meals.

Effectiveness of gastric sleeve surgery

This procedure results in rapid weight loss. However, about one in 5 people will regain some of the lost weight over time.

Side effects and complications of gastric sleeve surgery

Complications tend to happen in the first 2 weeks after surgery, and can include leaking from the cut edge of the stomach and bleeding.

Vomiting is uncommon after gastric sleeve surgery.

Gastric bypass surgery

Gastric bypass surgery is an option often recommended for people with a very high BMI. It involves a laparoscopic procedure to:

  • reduce the size of the stomach (to restrict the amount of food that can be eaten); and
  • create a passage for food to bypass the first part of the small intestine (where nutrients – and thus calories – are absorbed).

This operation also alters hormones that affect appetite and metabolism, and makes it difficult to digest sweet foods (eating sugary foods often results in an unpleasant side effect called dumping syndrome).

Effectiveness of gastric bypass

80 per cent of excess weight is expected to be lost within the first year. Weight loss tends to be maintained.

Complications and side effects of gastric bypass

There are some significant complications that can result from gastric bypass surgery, and the risk of death is about 1 in 100.

Dumping syndrome – when food (especially sugar) moves too quickly from the stomach to the small intestine – is a side effect that is associated with gastric bypass surgery. Dumping syndrome causes symptoms of nausea, vomiting, diarrhoea, cramps, anxiety and sweating after eating. Dietary changes can help control dumping syndrome.

Gastric balloon

Placement of a gastric balloon is the least invasive weight loss procedure. It involves having an endoscopy and an inflatable balloon being placed in the stomach and filled with liquid. This restricts the volume of the stomach so that less food can be comfortably eaten.

The procedure is easily reversible – the balloon can simply be removed with a gastroscopy. In fact, this procedure is usually regarded as a temporary weight loss option.

Effectiveness of gastric balloon

Gastric balloon results in an average weight loss of 10 per cent of starting weight after 6 months. The weight loss is maintained in about a third of people.

The balloon needs to be removed or replaced after 6 months.

Complications and side effects of gastric balloon

Nausea, vomiting and abdominal cramps are common in the week after the procedure. In some people, this does not settle, and the gastric balloon needs to be removed.Serious complications are uncommon.


Comparison of different types of bariatric surgery

ProcedureMay be suitable forRate of weight lossTime in hospitalTime off workSide effects/ complicationsIs it reversible?
Gastric balloonYounger people wanting to kick-start weight loss. Very obese people who need to lose some weight to make it safer for them to have a permanent form of weight loss surgery.About 10-15 kg weight loss is common. Most weight loss occurs in the first couple of months after the procedure.Usually done as day surgeryAbout one weekNausea, vomiting and abdominal cramps are common to start with. Serious complications are rare.Easily reversible
Gastric bandingPeople wanting long-term weight loss and a low-risk procedure.Weight is lost gradually over several yearsUsually requires an overnight stay in hospitalUp to one weekGastric banding has a low rate of complications during and after the procedure, but the band may need adjusting in a subsequent procedure.Reversible
Gastric sleeveThose with a higher starting weight and health problems related to obesity needing a long-term weight loss option.Weight is lost quickly, with most lost in the 1-2 years after the procedure.About 2-3 nights in hospitalAbout 2 weeksMost serious complications happen in the first 2 weeks after surgery. Late complications are rare.Not reversible
Gastric bypassThose with a higher starting weight and health problems related to obesity needing a long-term weight loss option.Weight is lost quickly, with most lost in the 1-2 years after the procedure.2-4 nights in hospitalAbout 2 weeksComplications are more common with this procedure. Ask your doctor about the risks.Reversal is possible, but can be difficult