The University of Bristol and National Institute for Health and Care Research (NIHR) study carried out at Musgrove Park Hospital found 68% (276) participants randomised to Bypass achieved at least 50% excess weight loss after three years, compared to 25% (97) for Band and 41% (141) for Sleeve surgeries.

Bypass also led to a greater reduction in comorbidities, such as high blood pressure and diabetes and was found to be the most cost-effective option when taking into account patients' quality of life using a standard UK cost threshold applied by NICE.

Although a more costly operation initially, Bypass led to better quality of life and lower healthcare costs after three years compared to the other two surgeries.

Professor Danny McAuley, scientific director for NIHR Programmes, said: ‘Obesity is one of the biggest challenges facing us globally and in the UK. This treatment will help save lives and improve the quality of life for patients, while providing better value for money for the NHS.

‘The findings demonstrate how our life changing NIHR research, funded by the public, has impact to support the health and care sector to achieve more effective and efficient use of resources.'