Bariatric and metabolic surgery: three figures missing from almost every brochure
No randomised trial has ever compared bariatric surgery directly with GLP-1 agonists. Of the diabetes remissions achieved by surgery, 58.8% had relapsed by ten years in the only trial with that follow-up, although everyone concerned still had adequate glycaemic control. And weight regain after bypass affects 44% or 67% of patients depending on the definition chosen, within the same group of 1,406 people. These figures describe populations, not one patient. Noria Health arranges a full metabolic work-up near Brussels within 24 to 48 hours.
The questions we are asked
- Are the injections as good as surgery?
- What happens if I stop the treatment?
- Sleeve or bypass, what changes at ten years?
- Can my diabetes be cured?
- Does remission last?
- What are the real risks of the operation?
- Will I regain the weight?
- What does metabolic surgery actually change?
What the figures say
| What is measured | The figure | Source and year |
|---|---|---|
| Weight loss on semaglutide in trials | -14.9% | STEP 1, NEJM, 2021 |
| Weight loss on semaglutide in the real world at 1 year | -5.4% | Brown, Obesity, 2026 |
| Weight loss after bypass in the real world at 1 year | -29.8% | Brown, 2026 |
| Regain after stopping tirzepatide over 52 weeks | +14.0% | SURMOUNT-4, JAMA, 2024 |
| Cardiovascular event reduction, semaglutide | 20%, HR 0.80 (0.72 to 0.90) | SELECT, NEJM, 2023 |
| Mortality reduction, surgery, 24-year cohort | HR 0.77 (0.68 to 0.87) | SOS, NEJM, 2020 |
| Diabetes remission at 12 years | 12.7% against 0.0% | ARMMS-T2D, JAMA, 2024 |
| Perioperative mortality, sleeve against duodenal switch | 0.05% against 0.41% | Robertson, Br J Surg, 2021 |
| Conversions at 10 years, sleeve against bypass | 29.9% against 5.5% | SM-BOSS, JAMA Surg, 2025 |
Those nine lines say one thing. In obesity, public debate pits two options against each other as though they had been compared. They have not. What is known is that the drug works while it is taken and surgery works once, that the first has a randomised trial on cardiovascular events and the second twenty-four years of mortality follow-up, and that the choice between sleeve and bypass turns mainly on reflux and conversion rates. That is a decision to make on those criteria, not on an isolated weight-loss percentage.
What Noria Health does in bariatric and metabolic surgery, and what it does not do
Noria Health arranges a full metabolic work-up near Brussels within 24 to 48 hours: nutritional and psychological assessment, full blood work with C-peptide, screening for microvascular and macrovascular complications, upper endoscopy with reflux assessment, and cardiovascular work-up. The report is issued within 24 hours, follow-up is structured at D14, D30 and D90, and surgery is considered only around day 10 if it is needed.
What Noria Health does not do: operate without prior psychological assessment or a nutritional follow-up plan, promise a cure for diabetes, or present surgery and injectable treatments as two interchangeable options. Persistent vomiting, acute abdominal pain, fever or collapse after bariatric surgery are matters for the emergency services in your country, immediately, not for an appointment.
Who reviewed this page
Noria Health editorial team.
The bariatric and metabolic surgery articles
- Surgery or GLP-1: no trial has ever compared them directly
- Diabetes: 58.8% of surgical remissions had relapsed by ten years
- Weight regain after bypass: 44% or 67% of patients, depending on the definition
- Metabolic surgery, what the trials measure
Have your case reviewed. Noria Health arranges a specialist consultation near Brussels and confirms feasibility within 24 to 48 hours. Open a case.