Weight loss largely held at seven years after one‑anastomosis gastric bypass in an 80‑patient series

Surgeons in Israel tracked 80 people for an average of seven years after one-anastomosis gastric bypass and reported that most of the early weight loss was still there. The paper went online on 10 September 2026 in Surgical Laparoscopy, Endoscopy and Percutaneous Techniques.

One-anastomosis gastric bypass, usually shortened to OAGB, turns the top of the stomach into a long narrow tube and joins it straight to a loop of small intestine using a single connection. The older Roux-en-Y gastric bypass uses two connections. OAGB is widely performed in parts of Europe, the Middle East and Asia, and much less often in the United States, so long-term published data on it is still thin.

Average excess weight loss was 80.2 percent at six months and 74.6 percent at seven years

The team reviewed the consecutive patients who had the operation at Shamir Medical Center during 2016, then called them for a structured interview in late 2024. Eighty people were included in the final analysis: 55 women and 25 men, average age 44.3 years, ranging from 20 to 68. Before surgery their average weight was 103.2 kg, about 228 pounds, and their average body mass index was 40.9.

Average BMI dropped to 28.1 by roughly a year and eight months after surgery and stayed near that level for the rest of the follow-up. The authors also reported excess weight loss, a measure that compares the weight a person lost against how far they were above a reference weight rather than against their starting weight. On that measure the average was 80.2 percent at six months and 74.6 percent at seven years. Excess weight loss always produces a bigger-sounding figure than percentage of total body weight lost, so it is worth checking which one a clinic is quoting.

Operations averaged 101.9 minutes and people stayed in hospital an average of 3.3 days. Major complications in the first 30 days were reported in 5.1 percent of cases. In a group this small that represents only a handful of people, so the true rate could be meaningfully higher or lower.

More than 80 percent of those with diabetes, high blood pressure, sleep apnea or high cholesterol were recorded as resolved

Among the patients who had type 2 diabetes, high blood pressure, obstructive sleep apnea or high cholesterol before surgery, the authors reported resolution in more than 80 percent of each group. Quality of life improved across the seven years on BAROS II, a bariatric scoring system that folds weight loss, change in other health conditions and patient-reported wellbeing into a single score.

The authors concluded that OAGB is straightforward to perform and safe, with short operating and hospital times, and that it produced durable weight loss and lasting quality-of-life gains.

Eighty patients from one hospital in one year is a narrow base

The strength here is the length of follow-up, not the size or design of the study. Seven-year data on OAGB is scarce, and this adds a data point. It does not establish how OAGB compares with sleeve gastrectomy or Roux-en-Y gastric bypass, because no other procedure was studied alongside it.