Types of Weight-Loss Surgery: Sleeve, Bypass, Band, and Balloon Compared
Key takeaways
- The main types of weight-loss surgery are the gastric sleeve, the gastric bypass, the adjustable gastric band, and the intra-gastric balloon.
- The sleeve removes about 70 to 80% of the stomach; the bypass also reroutes the intestine; both typically deliver the largest, most durable weight loss.
- The band and the balloon are less invasive and the band is reversible, but both tend to lose less weight, and the balloon stays in for only about 6 to 12 months.
- There is no single best operation: the right one is an individual decision made with a bariatric team, weighing your weight, health, and risks.
The main types of weight-loss surgery are the gastric sleeve, the gastric bypass, the adjustable gastric band, and the intra-gastric balloon: they work either by shrinking the stomach, by rerouting the gut, or both, and they differ in how much weight you lose, how invasive they are, and whether they can be reversed. There is no single best operation, only the one that fits you.
I had a sleeve in my forties after years of dieting, but it was not the only option on the table when I started reading. Understanding how each procedure works, and what it asks of you, made the eventual decision far less frightening. Here is the honest comparison I wish I had found first.
How the main types differ
Weight-loss (bariatric) surgery works in two broad ways. Restrictive procedures make the stomach much smaller so you feel full sooner; malabsorptive elements also reroute the gut so fewer calories are absorbed. The sleeve and the band are mainly restrictive; the bypass combines both; the balloon is a temporary restrictive device. The sleeve and bypass are the two most common operations worldwide and generally give the largest, most durable weight loss, with people typically losing about 60 to 70% of their excess weight over 12 to 18 months (NHS, ASMBS).
The gastric sleeve
The sleeve (sleeve gastrectomy) removes roughly 70 to 80% of the stomach, leaving a narrow, banana-shaped tube. It works two ways: restriction, and a hormonal effect (less ghrelin, so less hunger). It is done laparoscopically (keyhole), takes about 1 to 2 hours, and usually means a 1 to 2 night hospital stay.
Pros: a simpler operation than the bypass, with nothing rerouted and no implant left inside; it keeps strong weight loss. Cons: it is irreversible, and it can cause or worsen reflux. That reflux risk was the thing my surgeon flagged hardest, and it is a genuine reason some people are steered elsewhere. The full picture is in our gastric sleeve surgery guide, and how the gastric sleeve works goes deeper on the mechanism.
The gastric bypass
The Roux-en-Y gastric bypass creates a small stomach pouch and reroutes the small intestine to it, so you eat less and absorb fewer calories. Weight loss is typically as good as or slightly better than the sleeve, and it often controls type 2 diabetes and reflux more strongly.
Pros: powerful and well established, and a good choice when reflux is already a problem. Cons: it is a more complex operation, carries a higher chance of nutritional deficiencies, and can cause dumping syndrome (rapid emptying that brings nausea and lightheadedness after sugary food). Our gastric sleeve versus gastric bypass comparison weighs the two side by side.
The adjustable gastric band
An adjustable gastric band is a silicone ring placed around the upper stomach to create a small pouch; a port under the skin lets the team tighten or loosen it. It is the least invasive of the true operations and is reversible by removal.
Pros: adjustable and removable, with no part of the stomach taken away. Cons: weight loss is generally lower and slower than the sleeve or bypass, it needs regular adjustments, and it can slip or erode, so bands are placed far less often than they once were. The band suits people who want a reversible option and accept more modest results.
The intra-gastric balloon
The intra-gastric balloon is a soft balloon placed in the stomach by endoscopy (no incisions) and inflated, so you feel full on less food. It is temporary: it is removed after about 6 to 12 months.
Pros: non-surgical, no cuts, and fully reversible; useful as a shorter-term tool or a step before surgery. Cons: weight loss is usually smaller and can return once it is removed, and it commonly causes nausea in the first days. It is best thought of as a kick-start rather than a lasting fix.
Who each one suits
The right operation is an individual decision made with a bariatric multidisciplinary team, not a menu you pick from alone. Surgery is generally considered at a BMI of 40 or above, or 35 or above with an obesity-related condition such as type 2 diabetes, high blood pressure, or sleep apnoea; updated guidance lowers those thresholds for metabolic disease (NICE, ASMBS). The team weighs your weight, your other conditions, your eating patterns, and your own preferences about reversibility and recovery. If you are starting to wonder where you fit, our guide to whether you are a candidate walks through the criteria, and our look at the gastric sleeve versus diet and exercise sits alongside the question of how surgery compares with lifestyle change alone.
Whichever type is right, none is a quick fix: every option only works alongside lifelong changes to how you eat, plus follow-up and, for most, ongoing vitamins. Obesity is a medical condition, and choosing surgery is a serious, valid step, not a failure of willpower.
This guide is general information, not a diagnosis or a recommendation. Decisions about which operation is right for you should be made with a GP and a qualified bariatric team who can assess you individually.
References
- Weight loss surgery, NHS.
- Bariatric Surgery Procedures, American Society for Metabolic and Bariatric Surgery (ASMBS).
- Obesity: identification, assessment and management (CG189), NICE.
- Bariatric surgery, Mayo Clinic.
Frequently asked questions
What are the main types of weight-loss surgery?
The four most common are the gastric sleeve (sleeve gastrectomy), the gastric bypass (Roux-en-Y), the adjustable gastric band, and the intra-gastric balloon. The sleeve and bypass are the two most performed worldwide and usually give the biggest weight loss. The band is reversible but used much less now. The balloon is a temporary, non-surgical option placed by endoscopy.
Which type of weight-loss surgery is most effective?
The gastric bypass and the gastric sleeve generally produce the most weight loss, with people typically losing about 60 to 70% of their excess weight over 12 to 18 months. The bypass often loses slightly more and helps reflux, while the sleeve is a simpler operation. The band and the balloon usually lose less. The most effective one for you depends on your health and is decided with your bariatric team.
What is the safest weight-loss surgery?
All bariatric surgery is major and carries real risks, but mortality is low across the common procedures, roughly 0.1 to 0.3% for the sleeve. The intra-gastric balloon is the least invasive because it needs no incisions, and the adjustable band can be removed, but neither is risk-free and both tend to lose less weight. Safety is judged against the risks of staying at your current weight, individually with your team.
Is the gastric sleeve or gastric bypass better?
Neither is simply better; they suit different people. The sleeve is a shorter, simpler operation with no rerouting, while the bypass reroutes the intestine and often controls reflux and type 2 diabetes more strongly but carries a higher chance of nutritional deficiencies. Our gastric sleeve versus gastric bypass guide compares them in full so you can discuss the trade-offs with your surgeon.
Can weight-loss surgery be reversed?
It depends on the type. The adjustable gastric band can be removed and the intra-gastric balloon is taken out after about 6 to 12 months, so both are reversible. The gastric sleeve is not reversible, because the removed part of the stomach is gone, though it can sometimes be converted to a bypass. The bypass is technically reversible but rarely undone. Treat any surgical option as a lasting change.
How do I choose which weight-loss surgery to have?
You do not choose alone. A bariatric multidisciplinary team assesses your weight, your other health conditions such as type 2 diabetes or reflux, your eating patterns, and your goals, then recommends the option that fits. Your own preferences about reversibility and recovery matter too. The decision is made together, and every option only works alongside lifelong changes to how you eat.
Written by Claire Maddox. Medically reviewed by Mr Ian Calloway, MBBS, FRCS.
Our guides are written from personal experience and reviewed by a qualified clinician for accuracy. Read our editorial policy.