Eligibility for bariatric (weight loss) surgery is assessed based on BMI (Body Mass Index) and the presence of other clinical conditions, called “comorbidities”. Surgery for obesity is considered an appropriate choice for patients:

• With a BMI greater than 40
• With a BMI greater than 30 and one or more obesity-related comorbidities
• Who have tried non-operative weight loss solutions without long-term success
• In certain circumstances, patients with BMI lower than 30 may be candidates, though medication and life style changes are normally recommended.

You can estimate your BMI using our BMI calculator. You can read more about this in our patient education guide.

Weight loss depends on the type of surgery you have had, and on how well diet and post-op guidelines are followed. After a sleeve gastrectomy (the most used type of surgery), most people can expect to lose around 60% of their extra body weight¹. Most of this is lost within the first two years.

^{1: Žygimantas Juodeikis, Gintautas Brimas. 2016 Long-term results a=er sleeve gastrectomy: A systema?c review. Published by Surgery for Obesity and Related Diseases. DOI: hEps://doi.org/10.1016/j.soard.2016.10.006}

In preparation for the surgery, patients are asked to start their liquid diet, exercise, and refrain from consuming alcohol or smoking in the week prior to surgery. You can read more about this in our Surgery preparation guide.

Surgery can help you lose weight in different ways.

• Restrictive
• Restrictive and malabsorptive

Restrictive procedures (gastric sleeve) reduce the size of the stomach so you automatically eat less.

Malabsorptive procedures (gastric bypass) alter how the body absorbs food by bypassing part of the digestive tract so you absorb fewer calories.

Laparoscopic procedures

Today, the majority of weight-loss surgical procedures use laparoscopy. This means making a number of small incisions in the abdomen and inserting a laparoscope camera and surgical instruments, so the surgeon can perform the procedure using a video monitor. Laparoscopic surgery is less invasive than “open” procedures, which means a lower risk of infection, less scarring and faster recovery. You can read more about this in our Patient education guide.

Obesity-related medical problems will generally improve after weight loss surgery, with some going into full remission for some patients. These include:

• Obstructive sleep apnoea
• Type 2 diabetes
• Gastroesophageal reflux disease (GERD)
• High cholesterol
• Degenerative joint disease or orthopaedic problems
• High blood pressure
• Asthma
• Urinary incontinence

As with any surgery, there are some risks associated with weight loss surgeries. These include:

• Vomiting from eating too much too quickly and not chewing well
• Constipation
• Nutritional deficiencies such as anaemia and osteoporosis.
• Wound infections can occur up to three weeks after surgery. These can be treated with antibiotics, and sometimes require further surgery.

Complications that may develop following weight loss surgery include:

• Hernias
• Gallstones
• Ulcerations
• Gastric prolapses
• Severe scarring of the new stomach pouch
• Excess skin that may need to be removed in an additional surgery
• Dehydration
• Hair loss
• Kidney stones
• Hypoglycaemia

Rare but serious complications include:

• Bleeding in the stool, or black stools
• Leaks in new connections made by weight loss surgery; these usually occur within five days of surgery.
• Blood clots in the lungs (pulmonary emboli) rarely occur, but if they do, they are the most common cause of death after weight loss surgery. Blood clots can
  be usually prevented with blood thinning medicines and frequent activity.
• Blood clots in the legs, called deep vein thrombosis, or DVT
• Pneumonia

To avoid these complications, it is important you refer to the practice you trust the most, and keep an open communicaton with your doctor and GP before and after the procedure.