Dr Lockie's Blog

Roux-En-Y Bypass Demonstrates Superior Weight Loss

13th November 2025

Big UK Study Compared Three Bariatric Procedures

Whilst laparoscopic sleeve gastrectomy remains the commonest procedure in Australia, the results of a recent long-term study, the B-y- Band-Sleeve Study, demonstrated that the Roux-en-Y gastric bypass had superior weight loss results compared to the sleeve gastrectomy and gastric band.

The By-Band-Sleeve trial was a multicentre randomised controlled trial conducted in 12 hospitals in the UK. Endpoints were weight loss and quality of life score at 3 years. All of the centres had a specialist multidisciplinary bariatric team.

There were 4,140 eligible participants in the trial. 462 had a Roux-en-Y gastric bypass, 464 an adjustable gastric band, and 420 a sleeve gastrectomy. There was 86% follow-up at 3 years.

Excess Weight Loss Comparison - 50% Weight Loss - Three Years

• 68% of participants with a Roux-en-Y gastric bypass achieved at least 50% excess weight loss at 3 years
• 41% in the sleeve gastrectomy group achieved this level
• 25% in the adjustable gastric band group achieved the 50% weight loss.

At 3 years, the mean quality of life score was higher in the gastric bypass group compared to both the sleeve and the adjustable gastric band. However, the difference between the sleeve gastrectomy and the Roux-en-Y gastric bypass group was not statistically significant.

Mean Percentage Weight Loss at Three Years

Mean percentage weight loss at 3 years was - 26.8 in the Roux-en-Y group, -19.4 in the sleeve gastrectomy group, and -14 in the adjustable gastric band group. The Roux-en-Y gastric bypass group also had better improvement in their lipid profile.

The study was published in The Lancet Diabetes and Endocrinology, May 2025.

How Can Dr Lockie Help

Dr Lockie currently performs all three procedures as well as offering medical weight loss. To find out what is right for you, book in now for a fully Medibank funded consulation with our SCOPE Certified NP, Shirely Lockie.

She will conduct a full metabolic assessment, and provide information on your weight loss options. She can also provide a referral to a clincial appointment with Dr Phil Lockie.