Irish researchers are set to investigate the success of weight loss that comes about after a gastric bypass.

Researchers at University College Dublin (UCD) and Ulster University, along with a team from Florida State University in the US, aim to investigate whether long-term weight loss from gastric bypass is due solely to changes in appetite and food choices, or if it is also linked with changes in metabolic rate after surgery.

A gastric bypass is a type of bariatric (weight loss) surgery. During the procedure, a small stomach pouch is created with the intention of restricting the intake of food. A section of the small intestine is attached to this pouch and this allows food to bypass the lower stomach and other parts of the small intestine. This bypass reduces the body's absorption of nutrients which leads to a reduced calorie intake.

Bariatric surgery has been found to be successful for many people, with benefits including better mobility, a reduced risk of cancer and a reduced risk of suffering a heart attack. Furthermore, weight loss can be maintained for many decades.

The safety of this operation is considered to be in line with that of hip replacement or gall bladder surgery.

According to one of the lead researchers, Prof Carel Le Roux of UCD, losing weight is ‘relatively easy in comparison with maintaining weight loss'.

"Understanding how gastric bypass surgery works and why it is so easy for patients after surgery to make essential behavioural changes may be the key to helping more people achieve long-term success with and without surgery," he commented.

The researchers have been awarded €2.5 million as part of the US-Ireland Research and Development Funding Programme. This is a unique arrangement which involves funding agencies in the US, the Republic of Ireland and Northern Ireland. These combine their resources to enable the best researchers from Ireland and the US to work together on research to address important issues and generate valuable discoveries that will impact on patient care.

The UCD part of the study is being funded by the Health Research Board. According to its chief executive, Graham Love, obesity is a major health challenge worldwide, but this research ‘ has real potential to help us understand what influences people's behaviour and to advance the treatment of people with obesity'.