Bariatric surgery is a group of operations that reduce the size of the stomach — and, in some procedures, change the route food takes through the digestive system — to treat obesity and obesity-related conditions. It is not a cosmetic procedure. It is a medical treatment for a chronic condition, and it works alongside long-term changes to nutrition, activity and follow-up care.
Who bariatric surgery may be suitable for
Suitability is established by clinical assessment, not by weight alone. An assessment generally considers:
- Body mass index, and how your weight has changed over time
- Obesity-related conditions such as type 2 diabetes, high blood pressure, obstructive sleep apnoea, joint pain or fatty liver disease
- What has already been tried, including supervised diet, activity and medical weight management
- General health, surgical risk and fitness for anaesthesia
- Readiness for the long-term dietary and follow-up commitment that surgery requires
Some people are better served by non-surgical options. Establishing that honestly is part of the purpose of a consultation.
How bariatric surgery works
Bariatric procedures generally work through two mechanisms, usually in combination:
- Restriction — reducing the volume of food the stomach comfortably holds.
- Metabolic and hormonal change — altering gut hormone signalling that influences appetite, fullness and blood sugar regulation.
The second mechanism is why bariatric surgery often improves type 2 diabetes and other metabolic conditions, sometimes before substantial weight loss has occurred.
Recognised bariatric procedures include sleeve gastrectomy and gastric bypass. Which procedure is appropriate depends on your medical history, your weight, and your metabolic and digestive health. That is a clinical decision, made together, after assessment.
Potential benefits
Where surgery is appropriate and is followed by long-term care, bariatric surgery can support:
- Sustained weight loss that is difficult to achieve through diet and activity alone
- Improvement, and in some cases remission, of type 2 diabetes
- Improvement in blood pressure, cholesterol and obstructive sleep apnoea
- Reduced mechanical load on weight-bearing joints
- Improvements in mobility, energy and day-to-day quality of life
Outcomes vary considerably between individuals. No procedure guarantees a particular amount of weight loss, and results depend heavily on long-term follow-up and sustained lifestyle change.
Risks and considerations
All surgery carries risk, and those risks should be discussed openly rather than minimised.
- General surgical risks: bleeding, infection, blood clots and anaesthetic complications.
- Procedure-specific risks: leaks at staple lines, narrowing of the stomach or join, reflux, and internal hernia after bypass procedures.
- After rapid weight loss: gallstones, and changes in skin laxity.
- Long term: vitamin and mineral deficiency requiring lifelong supplementation and monitoring; permanent changes to how and how much you eat; the possibility of weight regain; and, in a minority of cases, the need for further surgery.
- Reversibility: some bariatric procedures cannot be reversed.
- Psychological adjustment: rapid physical change can be demanding, and support matters.
Preparing for surgery
Preparation is individual, and typically includes clinical assessment and investigations, a nutritional review, optimisation of conditions such as diabetes or sleep apnoea, guidance on smoking and alcohol, and planning practical support at home. Some patients are asked to follow a specific pre-operative diet. Your surgical team will give you instructions based on your procedure and your health.
Recovery
Bariatric procedures are usually performed with minimally invasive techniques, which generally means a shorter hospital stay and a faster return to daily activity than open surgery. Eating progresses in stages — from liquids, to soft textures, to regular foods — under the guidance of your team. Timelines differ by procedure and by patient, so you should follow the specific plan you are given rather than a general schedule.
Life after bariatric surgery
The procedure is the beginning of treatment, not the end of it. Long-term care generally includes ongoing follow-up appointments and blood tests, lifelong vitamin and mineral supplementation, attention to protein and hydration, gradual return to regular physical activity, and support for the behavioural and emotional side of a major change. Patients who stay engaged with follow-up tend to do better over time.
Alternatives to consider
- Medical weight management — non-surgical, clinically supervised treatment.
- Allurion Balloon — a swallowable gastric balloon.
- Continued supervised lifestyle and dietary programmes.
Dr. Khanna also performs robotic bariatric surgery, which refers to the surgical platform used rather than a different operation.
Frequently asked questions
Will I lose weight without changing how I eat?
No. Surgery changes how your body handles food and appetite, but it does not replace nutrition, activity and follow-up. The operation makes change achievable; it does not make it automatic.
Is bariatric surgery safe?
Bariatric surgery is performed routinely and, in carefully selected patients, is well established. It still carries real risks, which vary with your health and the procedure chosen. Those risks are assessed and discussed individually before any decision.
Will my type 2 diabetes improve?
Many patients see meaningful improvement, and some achieve remission. This cannot be promised for any individual, and depends on factors including how long you have had diabetes.
Will I need vitamins for life?
Generally yes. Lifelong supplementation and periodic blood tests are a standard part of care after bariatric surgery.
Can I regain weight afterwards?
Yes. Weight regain is possible, particularly where follow-up and dietary habits lapse. Long-term support is designed to reduce that risk.
How do I know which procedure is right for me?
You do not need to decide in advance. The purpose of the assessment is to match the procedure to your medical history and goals — or to advise against surgery if it is not appropriate.