The band that shrinks appetite

Gastric banding, as the procedure is known, is designed to reduce the size of a patient's stomach and so help reduce food intake.

During the operation, an inflatable band is placed around the upper part of the stomach. A saline solution is then pumped into the band, which tightens to create a small pouch with a narrow opening.

The width of the opening limits how quickly food leaves the pouch and passes into the rest of the stomach.

The idea is that patients will feel full more quickly and so consume less food. The device, officially called the Lap Band Adjustable Gastric Banding System, was approved for use in the U.S. as far back as 2001. Before this patients could have their stomach stapled or a gastric bypass. Both were major operations.

The band, on the other hand, can be fitted in as little as 30 minutes during keyhole surgery.

An access valve, which is placed under the skin of the abdomen, is used to tighten or loosen the band.

Patients still have to limit their diet and exercise if they want to maintain weight loss. A study of nearly 300 found they lost more than a third of their excess weight over three years.

But almost all suffered at least one complication including the band slipping, nausea or abdominal pain.