Surgery Comparison Centre 2.0

Compare the operation — not just the headline weight loss.

Sleeve, Roux-en-Y bypass, OAGB/mini bypass, gastric band, balloon and ESG compared across anatomy, weight-loss evidence, reflux, diabetes, reversibility, nutrition, recovery, revision and NHS relevance.

Updated 8 August 20266 procedure typesX vs Y battleUK/NHS context
There is no single “best bariatric operation”.

A procedure that looks strongest for average weight loss may create a less attractive reflux, nutrition or permanence trade-off for a particular person. The comparison needs to look beyond kilograms.

Procedures at a glance

ProcedureTypeRelative weight-loss effectReversible?Reflux contextNutrition burdenNHS context
Sleeve gastrectomyLaparoscopic surgeryHighNoCan worsen or cause reflux in some peopleLong-term vitamin/mineral supplementation and monitoring requiredCommon NHS bariatric procedure where specialist assessment supports it
Roux-en-Y gastric bypassLaparoscopic surgeryVery highTechnically revisable but not treated as a simply reversible procedureOften considered favourable where significant reflux is a major issueHigher long-term micronutrient burden than sleeve; lifelong supplements and blood monitoring are importantEstablished NHS bariatric procedure
One-anastomosis gastric bypassLaparoscopic surgeryVery highRevisable but not a simple reversible treatmentBile reflux is an important procedure-specific considerationMeaningful micronutrient/protein malabsorption risk; long-term monitoring essentialOffered by some NHS bariatric centres; not universal
Adjustable gastric bandLaparoscopic surgery with implanted adjustable bandModerateYes, removableCan cause/worsen reflux, regurgitation or swallowing symptomsNo intestinal malabsorption, but diet quality and follow-up still matterMuch less prominent in modern NHS bariatric practice than historically
Intragastric balloonEndoscopic temporary deviceLow to moderateYes, temporary/removableCan worsen reflux/nausea in some peopleNo intestinal malabsorption, but adequate nutrition and structured follow-up still neededLimited/selective availability; not a routine substitute for bariatric surgery
Endoscopic sleeve gastroplastyEndoscopic suturing procedureModeratePotentially revisable/reversible in some circumstances, but not equivalent to simply 'undoing' a bandMay be preferable to sleeve in some reflux contexts, but individual assessment mattersLower malabsorptive burden because intestine is not bypassedNHS now describes ESG as a weight-loss procedure, but availability is not universal

Procedure Battle

Pick any two procedures

VS

Big decisions that often change the procedure discussion

Reflux

Sleeve can worsen reflux in some people, while Roux-en-Y bypass can be a more attractive discussion where reflux is significant. This needs surgeon-level assessment rather than a website rule.

Type 2 diabetes

Bypass procedures have particularly strong metabolic evidence. Diabetes severity, medicines and individual anatomy still matter.

Long-term nutrition

All bariatric patients need follow-up, but bypass procedures carry a greater malabsorptive/micronutrient burden than purely restrictive or endoscopic procedures.

Reversibility

A gastric band is removable; sleeve removes stomach permanently. ESG avoids resection but should not be marketed as if it were a zero-commitment procedure.

Recovery

Endoscopic options generally recover faster than laparoscopic surgery, but procedure intensity is only one part of the decision.

Revision

Weight regain, reflux, malnutrition and device problems can all create revision pathways. “One operation forever” is not guaranteed.

NHS assessment threshold

NICE recommends referral for comprehensive bariatric-surgery assessment for adults with BMI 40 kg/m² or more, or BMI 35–39.9 kg/m² plus a significant health condition that could improve with weight loss, subject to the full guideline and specialist assessment. Lower BMI thresholds can apply for some ethnic groups. Referral is not the same as being offered a particular operation.

Read the NHS surgery pathway guide →

Direct comparisons

What the NHS now describes

The NHS weight-loss surgery pages cover gastric bypass, gastric band, gastric balloon and sleeve gastrectomy, and its procedure guide also describes endoscopic sleeve gastroplasty (ESG). That does not mean every NHS bariatric service offers every procedure. Procedure choice and local availability remain specialist-service decisions.

Core sources

Weight loss is only one column.

A useful surgery decision also considers reflux, diabetes, nutritional risk, permanence, recovery, follow-up, revision and the patient's willingness to live with the procedure for decades.

Read surgery comparison methodology →

Chosen a procedure — now choosing where?

Compare UK and overseas surgery on true cost and the complete aftercare pathway.

Compare UK vs overseas

Surgery vs medication or lifestyle?

Cross category boundaries in the Universal Comparison Centre.

Open Universal Comparison

Need help thinking beyond the procedure?

The Shift Programme keeps the wider health, support and maintenance picture visible.

Considering surgery?

Take a structured question list into your consultation.

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