A group of weight-loss surgeries in which changes are made to the digestive system, some of which are non-reversible. The idea behind these types of surgeries is to help the patient lose weight by limiting the amount of food they can consume/digest at any one time. Bariatric surgeries should only ever be the final option when diet and exercise have proved inadequate and there are now serious health concerns caused by a person's weight.

The three most common types of Bariatric Surgeries are as follows:

1. Gastric Sleeve - The most common surgery, in which the stomach is irreversibly reduced to about 15% of its original capacity by surgically removing a large portion of it, resulting in a sleeve or tube-like structure.

2. Gastric Bypass - A more complicated procedure in which the stomach is divided into two parts; a small upper pouch and a large lower ‘remnant’ pouch. The small intestine is rearranged accordingly, bypassing the large pouch and thus significantly reducing the volume of the stomach.

3. Gastric Band - An inflatable silicone device is fitted around the top portion of the stomach to create a smaller stomach pouch. The device can be removed when the patient reaches their desired weight.

Alternatively, there is a non-surgical Bariatric procedure, known as the Gastric Balloon. This involves an inflatable device being temporarily inserted into the stomach via endoscopic placement. The balloon or balloons obstruct a sizable area of the stomach, thus reducing the amount of food it can contain at any one time and thus leading to eventual weight loss. The balloons are usually removed after 6 or 12 months.