Who is it for?
International guidelines (ASMBS/IFSO, 2022) recommend considering metabolic and bariatric surgery for adults with:
- a BMI of 35 kg/m² or more, with or without obesity-related disease; or
- a BMI of 30–34.9 kg/m² with type 2 diabetes or other metabolic disease not controlled by medical treatment.
Because people of Asian origin develop diabetes and heart disease at lower weights, these thresholds are often lowered – surgery may be considered from a BMI of about 27.5 kg/m² with poorly controlled diabetes. Candidates should have tried supervised lifestyle and medical weight management, and be ready to commit to lifelong follow-up.
Common procedures
Laparoscopic sleeve gastrectomy
About 75–80% of the stomach is removed, leaving a narrow tube or "sleeve". The smaller stomach holds less food and produces less ghrelin, the hunger hormone. It is the most commonly performed bariatric operation worldwide. It may worsen acid reflux in some patients.
Roux-en-Y gastric bypass (RYGB)
A small stomach pouch is created and joined to a loop of small intestine, bypassing most of the stomach and the first part of the bowel. It gives excellent diabetes control and helps reflux, but needs strict vitamin and mineral supplements.
One-anastomosis (mini) gastric bypass
A long, narrow pouch is joined to the intestine with a single connection. It is technically simpler with strong weight-loss and diabetes results, but bile reflux can be a concern.
Endoscopic options
Intragastric balloons and endoscopic sleeve gastroplasty are non-surgical options for selected patients with lower BMI, though weight loss is generally smaller and less durable.
What results can you expect?
Most patients lose 60–70% of their excess weight (roughly 25–30% of total body weight) within 12–18 months. Many see improvement or remission of type 2 diabetes, high blood pressure, sleep apnoea, fatty liver, joint pain and PCOS. Long-term success depends on diet, activity and follow-up.
Before surgery
- Blood tests, ultrasound of the abdomen, upper GI endoscopy, heart and lung assessment.
- Dietitian and psychological evaluation.
- A low-calorie liver-shrinking diet for 1–2 weeks before surgery.
- Stopping smoking at least 6 weeks before surgery.
Recovery and diet stages
Most patients stay in hospital 2–3 days and return to desk work in 2–3 weeks. The diet progresses gradually:
- Weeks 1–2: clear and then full liquids, small sips throughout the day.
- Weeks 3–4: pureed foods with a focus on protein.
- Weeks 5–6: soft foods.
- From week 6–8: regular healthy foods in small portions, eaten slowly.
Lifelong multivitamins, vitamin B12, iron, calcium and vitamin D are usually required, with blood tests every 6–12 months.
Risks
Bariatric surgery today is about as safe as gallbladder surgery in experienced centres. Possible complications include leak from the staple line, bleeding, blood clots, narrowing, ulcers, gallstones, nutritional deficiencies, dumping syndrome (after bypass) and reflux (after sleeve).
Frequently asked questions
Will I regain the weight?
Some regain (10–20% of the weight lost) is common after 2–5 years. Regular follow-up, protein-rich eating and exercise help keep it off; revision surgery is possible if needed.
Can I get pregnant after bariatric surgery?
Yes, and fertility often improves. Doctors usually advise waiting 12–18 months until weight stabilises, with close nutritional monitoring during pregnancy.
Is bariatric surgery covered by insurance?
In many countries, including India, several insurers cover bariatric surgery when medical criteria (BMI plus related illness) are met. Check your policy wording and waiting periods.
Last reviewed: October 2026. This page is general information and does not replace advice from your own doctor.