How Much Weight Do You Lose With a Gastric Sleeve? The Data

On average, people lose about 25% of their total body weight in the first year after a gastric sleeve. In a large U.S. study, average weight loss was 25.2% at one year and 18.8% at five years, showing some regain over time (Arterburn et al., 2018). For a person who weighs 300 pounds, 25% would be about 75 pounds. Results vary a lot from person to person.

Two ways weight loss is measured

You will see two kinds of numbers, and they are easy to mix up:

• Total weight loss (%TWL) is the share of your starting weight that you lose. Losing 60 pounds from 240 is 25% TWL.
• Excess weight loss (%EWL) is the share of your extra weight, above a healthy weight for your height, that you lose. This number is always larger, which is why clinic ads often use it.

When you compare programs or studies, check which one is being quoted.

Gastric sleeve weight loss timeline

Sources: MedlinePlus: life after weight-loss surgery, MedlinePlus: vertical sleeve gastrectomy, Arterburn et al., SLEEVEPASS 5-year, SLEEVEPASS 10-year, SM-BOSS long-term.

What those averages look like in pounds

Here is what the U.S. averages would mean at different starting weights. This is simple math on the study averages, not a prediction for any one person.

Percentages from Arterburn et al. (2018).

What the main studies found

Large U.S. study (PCORnet)

This study tracked tens of thousands of U.S. adults after bariatric surgery. Sleeve patients lost an average of 25.2% of their weight at one year and 18.8% at five years. Bypass patients lost more (31.2% and 25.5%), and gastric band patients less (13.7% and 11.7%) (Arterburn et al.). Because patients chose their own operation, the groups may differ in ways that affect results.

Finnish randomized trial (SLEEVEPASS)

In this trial, 240 adults with a starting BMI around 46 were randomly assigned to sleeve or bypass. Sleeve patients lost an average of 49% of their excess weight at five years (Salminen et al., 2018). At ten years, the median was 43.5%, but individual results ranged from 2.1% to 109.2% (Salminen et al., 2022). That range shows how differently people respond.

Swiss randomized trial (SM-BOSS)

After 10 years or more, sleeve patients had lost an average of 25.5% of their total body weight, not significantly different from bypass (Kraljevic et al., 2025). But 29.9% of sleeve patients had a second operation to convert to another procedure, mainly for reflux or not enough weight loss.

Why some people lose more than others

The research doesn't let us predict any one person's result, but several things clearly matter:

• Following the eating plan. MedlinePlus says the sleeve is not a quick fix. Without healthy food choices, small portions and exercise, weight loss can be poor and complications more likely (MedlinePlus).
• Follow-up care. ASMBS calls preoperative education, continuity of care and long-term follow-up essential parts of successful outcomes (ASMBS).
• Starting weight. Someone who starts heavier usually loses more pounds, even if the percentage is similar.
• Time. Averages drop between year one and year five, which reflects some weight regain in many patients (Arterburn et al.).

Weight regain: what to know

Some regain after the first year or two is common, as the drop from 25.2% to 18.8% average loss in the U.S. study suggests (Arterburn et al.). MedlinePlus advises talking to your provider if you start gaining weight or stop losing it, and reviewing what and how much you are eating and drinking (MedlinePlus). Options for people who regain weight or develop severe reflux can include a second operation, often a conversion to gastric bypass, as seen in the Swiss trial (Kraljevic et al.).

Health changes beyond the scale

Weight loss is only part of the picture. In the Finnish trial, about 37% of sleeve patients with type 2 diabetes were in full or partial remission at five years, and 29% had stopped their blood pressure medicine (Salminen et al.). MedlinePlus lists conditions that may improve with weight loss after a sleeve, including type 2 diabetes, high blood pressure, sleep apnea, high cholesterol and arthritis (MedlinePlus).

Who is usually a candidate

MedlinePlus describes the traditional criteria for weight-loss surgery as a BMI of 40 or more, or a BMI of 35 or more with a serious condition that might improve with weight loss, such as sleep apnea, type 2 diabetes or heart disease (MedlinePlus). In 2022, ASMBS and the international surgery federation IFSO published major updates to the older 1991 NIH guidelines (ASMBS/IFSO, 2022). Ask your surgeon which criteria apply to you, and how your BMI and health conditions shape realistic expectations.

Sleeve vs other operations

MedlinePlus notes the final weight loss after a sleeve may not be as large as after gastric bypass, which may still be enough for many people (MedlinePlus). In randomized trials the gap was modest; in the large U.S. study it was larger. For a full comparison of weight loss, reflux and risks, talk to your surgeon about which operation fits your health.

If you have your sleeve abroad

Long-term weight loss depends on follow-up, which is harder when your surgeon is in another country. ASMBS recommends setting up follow-up with a local bariatric program before surgery, to monitor nutrition and long-term complications and to provide dietary and psychological support (ASMBS). Ask your surgeon abroad for your operative report and records in English (CDC), and write down your starting weight so your U.S. team can track your progress.

Compare programs for the gastric sleeve in Mexico or in Tijuana, read Is a gastric sleeve in Mexico safe?, and check what insurance covers abroad before you book.

The bottom line

A typical sleeve patient loses about a quarter of their body weight in the first year, with some regain later and an average near 19% at five years in U.S. data. Ten-year trials show lasting results for many people, but a wide range and a meaningful share who need a second operation. Your own result depends heavily on the eating habits, activity and follow-up care you build after surgery, so plan those before you book.