Short answer
Yes, bariatric surgery can put type 2 diabetes into remission, meaning blood glucose stays below the diabetes range without diabetes medicines, but it does not do so for everyone and remission does not always last.1 In long-term randomised trials, remission rates after surgery were clearly higher than with medical and lifestyle treatment, yet fell over time, to about 1 in 8 people at 12 years.2 The chance of remission depends mainly on how long a person has had diabetes, whether they use insulin and which operation they have.3
Key points
- Remission means an HbA1c below 48 mmol/mol (6.5%) for at least 3 months without glucose-lowering medicines.1
- Remission rates are highest in the first years after surgery and decline later.23
- Even without full remission, blood glucose control is usually better than before surgery.2
- Shorter diabetes duration and not needing insulin are linked to higher remission rates.3
- People in remission still need at least yearly checks, including eye screening.1
What “remission” means
Type 2 diabetes is usually monitored with HbA1c, a blood test that reflects average glucose levels over the previous two to three months. Diabetes UK defines remission as HbA1c returning to below 48 mmol/mol (6.5%) and staying there for at least 3 months without any glucose-lowering medication.1
Remission is deliberately not called a cure. Diabetes UK states there is currently no evidence that remission is permanent and that diabetes can come back.1 Remission can follow substantial weight loss by several routes, including intensive dietary change as well as bariatric surgery (operations on the stomach or intestine to treat obesity).1
What the long-term trials show
The strongest long-term evidence comes from a pooled analysis of four US randomised trials (studies in which participants are allocated to treatments by chance). In total, 262 adults with type 2 diabetes and an average body mass index (BMI) of about 36 were followed for a median of 11 years after being assigned to either medical and lifestyle management or surgery: gastric bypass, sleeve gastrectomy or an adjustable gastric band.2
| Outcome | Medical and lifestyle management | Bariatric surgery |
|---|---|---|
| Diabetes remission at 7 years | 6.2% | 18.2% |
| Diabetes remission at 12 years | 0% | 12.7% |
| Change in HbA1c at 7 years | Down 0.2 percentage points | Down 1.6 percentage points |
| Diabetes medicines | More | Fewer |
| Side effects more common | None specifically reported | Anaemia, fractures and gut-related problems |
At 12 years, the difference in HbA1c between the groups was still about 1.1 percentage points in favour of surgery.2 There was no difference in major heart and circulation events or in deaths, although the trials were not large enough to detect small differences in these outcomes.2
The evidence that surgery improves glucose control and remission compared with medical treatment is Strong, as it comes from randomised trials with long follow-up. The evidence on exactly how many people stay in remission for decades is more uncertain, because numbers in these trials were modest and some participants were lost to follow-up.
Why remission rates fall over time
In the trials above, remission after surgery dropped from 18.2% at 7 years to 12.7% at 12 years.2 Shorter-term studies show higher figures: a Canadian hospital study of 207 people found that about half were in remission one year after surgery, and of those followed to two years, about 1 in 7 had already relapsed.3
These studies do not fully explain why some people relapse, and the reasons are likely to vary from person to person. Because diabetes can return, Diabetes UK recommends that everyone in remission keeps having regular monitoring, at least once a year, including retinal (eye) screening.1
Who is more likely to reach remission
In the Canadian study, three factors were independently linked to remission at one year:3
- Shorter duration of diabetes: the odds of remission fell with each additional year of diabetes.
- Not using long-acting insulin: people who needed insulin were much less likely to reach remission.
- Type of operation: about 58% reached remission after gastric bypass, compared with about 38% after sleeve gastrectomy.
This was a single-centre review of past records rather than a trial, so the evidence for these predictors on their own is Limited. Larger and longer studies are needed to confirm how well they predict remission for an individual.
How diabetes affects eligibility for surgery
In the NHS, weight-loss surgery may be considered for people with a BMI of 40 or more, or a BMI between 35 and 40 together with a condition that might improve with weight loss, such as diabetes or high blood pressure.4 For people from South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean family backgrounds, surgery may be considered at a BMI below 40.4 Whether surgery is appropriate for a particular person depends on a full assessment by a specialist team.
Common questions
If I do not reach remission, was surgery pointless?
Not necessarily. In the long-term trials, people who had surgery had lower HbA1c and needed fewer diabetes medicines than those treated medically, even though most were not in full remission.2
Is gastric bypass better than a sleeve for diabetes?
In the Canadian study, remission at one year was more likely after gastric bypass than after sleeve gastrectomy, but this came from past records rather than a direct trial.3 The choice of operation also depends on other individual factors that a specialist team weighs up.
Can I stop my diabetes medicines straight after surgery?
Only under medical supervision. Medicines are adjusted by the clinical team, and remission is only confirmed after at least 3 months off medication with HbA1c below the diabetes range.1
Do I still need diabetes checks if I am in remission?
Yes. Diabetes UK advises at least annual monitoring, including eye screening, because diabetes can return.1
Bottom line
Bariatric surgery is one of the few treatments shown in trials to produce diabetes remission, and it improves glucose control even when remission is not reached. Remission is most likely when diabetes is recent and insulin is not needed, and it should be seen as a period to protect with ongoing monitoring rather than a permanent cure.
Related reading
- Gastric bypass guide
- Who Qualifies for Weight-Loss Surgery?
- Gastric Sleeve vs Gastric Bypass: How Do They Compare?
- Weight-Loss Injections vs Surgery: How Do They Compare?
- Can Weight Come Back After Bariatric Surgery?
Sources
- Diabetes UK. Our position statement on remission of type 2 diabetes. Diabetes UK; 2021. https://diabetes.org.uk/professionals/position-statements-reports/statement-remission-type2. Accessed 5 November 2026.
- Courcoulas AP, Patti ME, Hu B, Arterburn DE, Simonson DC, Gourash WF, et al. Long-term outcomes of medical management vs bariatric surgery in type 2 diabetes. JAMA; 2024. https://repository.lsu.edu/pbrc_basic_science_pubs/150. Accessed 5 November 2026.
- Dang JT, Sheppard C, Kim D, Switzer N, Shi X, Tian C, de Gara C, Karmali S, Birch DW. Predictive factors for diabetes remission after bariatric surgery. Canadian Journal of Surgery; 2019. https://www.canjsurg.ca/content/cjs/62/5/315.full.pdf
- NHS. Weight loss surgery: why it’s done. NHS website; 2024. https://www.nhs.uk/tests-and-treatments/weight-loss-surgery/why-its-done/. Accessed 5 November 2026.
Article history
- — First published.