Bariatric Surgery (Surgical Treatment for Obesity)


Obesity refers to the problem of excessive accumulation of body fat. According the World Health Organisation (WHO), individuals with a body mass index (BMI, calculated by dividing an individual’s weight in kg by the square of their height in m) level above 30 kg/m2 are defined as obese. Obesity is not a cosmetic problem and was recognised as a disease by the American Medical Association in 2013.

Causes of obesity

If you eat more calories than your body uses, you will accumulate excess body fat. Over time, this leads to obesity. Obesity risk factors include genetic makeup, overeating, consumption of high-energy foods and lack of physical activity.

Consequences of obesity

Obesity increases the risk of both medical and physical disorders such as diabetes mellitus, heart disease, stroke, polycystic ovarian syndrome, fatty liver, obstructive sleep apnoea, back pain, arthritis, and some cancers. Weight loss can dramatically improve these conditions in obese individuals. Bariatric surgery is the most powerful treatment designed to consistently achieve weight loss greater than 20% of body weight. Motivated individuals can lose up to 50% of their body weight.

What is Bariatric Surgery?

Bariatric surgery, also known as weight loss surgery, includes a variety of procedures performed to combat obesity. The size of the stomach is reduced with a gastric band, or through stapling / removal of a portion of the stomach, or by re-routing the small intestine to a small stomach pouch (gastric bypass surgery) to achieve weight loss.

All procedures are performed by keyhole technique in approximately 1-2 hours. Patients can usually go home the next day after the procedure.

The common bariatric surgeries widely used for weight loss include:

  • Laparoscopic gastric bypass
  • Adjustable gastric banding
  • Sleeve gastrectomy


Laparoscopic gastric bypass is the oldest bariatric procedure. Laparoscopic gastric bypass promotes weight loss by considerably restricting the amount of food you can eat, reducing calorie absorption, and suppressing hunger through promoting the feeling of fullness. The surgery does not require any organ removal or planting of any foreign objects.

How it works

The stomach is divided into a small “pouch” that the food eaten will enter, and one large “remnant stomach” that food will no longer enter. The remnant stomach is not removed, and still produces useful digestive juices which meet up with the food in the lower part of the digestive tract.

The new stomach is linked directly to a portion of the small intestine, bypassing the larger chamber created by the surgery. This allows for much smaller meals and less calorie consumption without feeling hungry. Re-directing the food stream causes changes in stomach hormones, which supresses hunger and promotes fullness.


Adjustable gastric banding is a procedure to reduce the entry of food into the stomach by placing a ring around the inlet of the stomach.

How it works

The band is a silicone tube which wraps around the upper part of the stomach to create a ring. The band is attached to a thin tube leading to an access port that is implanted under the skin.

Adding fluid into the access port tightens the band and controls the amount of food eaten. Taking away fluid can reduce the tightness and allow patients to eat more easily. After recovery from the surgery, the band can be adjusted to tighten the stomach and reduce food intake within 4-6 weeks.


Sleeve Gastrectomy is a procedure to make the stomach smaller through limiting the amount of food the stomach can hold. Approximately 75 – 80 percent of the stomach is stapled, leaving a sleeve or tube like structure. The surgery permanently reduces the size of the stomach, but in most cases, there is some dilatation of the stomach after 1-2 years. This allows individuals to adjust their eating habits and lifestyle to maintain a weight loss of 20 – 30% on average.

How it works

The new stomach holds a significantly smaller amount, hence it reduces the amount of food that can be consumed. This automatically reduces the number of calories consumed. The surgery also reduces the levels of “appetite” hormones, keeping hunger under control, promoting satiety, and regulating blood sugar.