Illustration · StomachBeforeAfter
What the data actually shows
Published outcomes across large series, stated as ranges because that is how the evidence reads.
| Procedure | At 12–18 months | At 5 years | Notes |
|---|---|---|---|
| Sleeve gastrectomy | 55–70% of excess weight | 45–60% | Reflux can worsen; a minority convert to bypass |
| Gastric bypass | 65–80% of excess weight | 55–70% | Better for reflux and type 2 diabetes; lifelong supplements |
| Mini gastric bypass | 65–80% | 55–70% | Technically simpler; bile reflux in a minority |
| Revision surgery | Variable, typically lower | Variable | Higher complication rate; expectations should be lower |
How to read "excess weight loss"
It is the percentage of weight above your ideal body weight that you lose — not the percentage of your total weight. Someone of 140 kg with an ideal weight of 70 kg has 70 kg of excess; losing 65% of that is 45 kg, taking them to 95 kg rather than to 70. Clinics quote the percentage because it is the larger number. Ask for the expected weight in kilograms instead, which is what the weight-loss surgery calculator on this site gives you.
What also improves
- Type 2 diabetes goes into remission in roughly 60–80% of cases after bypass, often within weeks and before much weight has gone.
- Obstructive sleep apnoea improves substantially in most patients, frequently to the point of stopping CPAP.
- Hypertension improves or resolves in around half.
- Joint pain, mobility and fertility typically improve markedly.
- These are the outcomes a clinician cares about most, and none of them appear in a photograph.
What the first two years actually look like
Including the plateau, which arrives for almost everyone and is routinely mistaken for failure.
| When | What happens | Typical loss |
|---|---|---|
| Weeks 1–4 | Liquid then pureed diet. Rapid loss, much of it fluid | 5–10 kg |
| Months 2–3 | Soft foods, then normal textures. Fastest sustained period | 10–18 kg total |
| Months 4–6 | Steady loss, energy returning, exercise becomes realistic | 20–30 kg total |
| Months 6–9 | Loss slows noticeably. The plateau most people panic about | 25–35 kg total |
| Months 9–18 | Slower, continuing loss toward the lowest point | 30–45 kg total |
| Months 18–24 | Weight stabilises. Some regain is normal and expected | Settles 10–20% above the lowest point |
What determines where you end up
- Protein intake, every day, permanently. The single most modifiable factor and the one most often neglected.
- Supplements — lifelong after bypass, and usually after sleeve. Deficiency is the commonest avoidable long-term complication.
- Resistance exercise, which protects muscle mass. Losing weight as muscle is how a good result becomes a poor one.
- Follow-up. Patients with structured follow-up keep meaningfully more weight off at five years than those without, which is the strongest argument against treating surgery abroad as a transaction.
- Addressing why you ate. Surgery restricts the stomach; it does nothing to the reasons, and this is where most late regain comes from.
What surgery does not fix
Said plainly, because the photographs imply otherwise and the gap causes real harm.
- Why you ate. Stress, boredom, grief and habit survive the operation untouched. Where food was the coping mechanism, something has to replace it, and that work is not surgical.
- Loose skin. Large losses leave it, and it is the thing patients most often say they were not warned about. Body contouring is a separate procedure, a separate cost, and usually at least 18 months later.
- Your relationship with your body. People routinely report that they still see the old body in the mirror a year after the weight has gone. It is well described and it does not resolve on a schedule.
- Other people’s reactions. Some relationships do not survive a transformation, and the effect on a partnership is underestimated by almost everyone going in.
- Alcohol risk. Transfer of a food-based coping mechanism to alcohol is a recognised post-bariatric pattern, more so after bypass, where absorption also changes.
- The need for follow-up. This is lifelong. Anyone selling bariatric surgery as a one-week trip with no ongoing care is selling you the operation and none of the treatment.
Loose skin, and what to do about it
The part almost no gallery shows, and the question we are asked most often after month twelve.
What determines how much you get
- How much weight you lose. Above roughly 40 kg, significant excess skin is the norm rather than the exception.
- Age. Skin elasticity declines, and the difference between thirty and fifty-five is substantial.
- How long you carried the weight. Years of stretch matter more than peak weight.
- Genetics and skin quality, which you cannot change.
- Rate of loss, slightly — though slower loss helps less than people hope.
- Smoking, which affects skin quality and surgical healing if contouring follows.
What helps, and what does not
- Helps: resistance training, which fills the frame with muscle; adequate protein; keeping weight stable once you reach it; time — skin retracts for 18–24 months.
- Does not help: creams, wraps, massage devices and supplements marketed for skin tightening. None of them do anything, and some of them are expensive.
- Works, but is surgery: body contouring — abdominoplasty, arm lift, thigh lift, breast lift, lower body lift — typically at least 18 months after surgery and only once weight has been stable for six.
Our body lift after weight loss page sets out what each contouring procedure involves, including the scars, which are extensive and permanent. The honest summary: contouring trades loose skin for a better shape and a long scar, and whether that is worth it is genuinely a personal judgement rather than a clinical one.
Weight-loss results: frequently asked questions
Typically 55–70% of excess weight after a sleeve and 65–80% after a bypass, at 12–18 months. Ask for the figure in kilograms rather than as a percentage — clinics quote the percentage because it is the larger number.
The percentage of weight above your ideal body weight that you lose, not of your total weight. Someone of 140 kg with an ideal of 70 kg losing 65% of their excess reaches 95 kg, not 70.
Most people regain 10–20% of what they lost, usually between years two and five, and settle well below their starting weight. The strongest predictor of where you end up is whether anyone was still supporting you at year three.
Almost certainly not. The plateau at months six to nine happens to nearly everyone as metabolic rate adjusts. It is a physiological adjustment, not a failure, and giving up during it is what causes poor long-term results.
Bypass generally produces more loss and is better for reflux and type 2 diabetes, at the cost of lifelong supplements and a more complex operation. Sleeve is simpler but can worsen reflux. The right answer depends on your case, not on price.
Above about 40 kg of loss, significant excess skin is the norm. Age, how long you carried the weight and skin quality matter more than how fast you lose. It is the thing patients most often say nobody warned them about.
No. Nor do wraps, massage devices or supplements sold for it. What helps is resistance training, adequate protein, stable weight and time — skin retracts for 18–24 months.
Usually at least 18 months after surgery and only after six months of stable weight. It trades loose skin for a better shape and a long permanent scar, and whether that is worth it is a personal judgement.
In roughly 60–80% of cases after bypass, often within weeks and before much weight has gone. Sleep apnoea improves substantially in most patients and hypertension in around half. These matter more clinically than the weight.
After bypass, yes, and usually after sleeve too. Deficiency is the commonest avoidable long-term complication, and it is entirely preventable with a daily routine and annual bloods.
No. It restricts the stomach and does nothing to stress, boredom, grief or habit. Where food was the coping mechanism, something has to replace it, and that is where most late regain comes from.
BMI below the threshold, uncontrolled eating disorder, untreated substance dependence, no plan for lifelong supplements and follow-up, or a decision that is not clearly the patient’s own. It is the procedure where we decline the highest proportion, deliberately.
