If you’re considering bariatric surgery, you’re not alone. For morbidly obese individuals, procedures like gastric sleeve and gastric bypass are highly effective weight loss solutions that address excess weight, health issues, quality of life, and life expectancy. Bariatric surgery is the tipping point that helps patients break through obesity and the lifelong struggle of unhealthy eating habits.

One of the most popular questions that we hear is, ‘How much weight will I lose with bariatric surgery?’

In this article, we cover all aspects of the bariatric surgery weight loss timeline chart. Our calculator helps you predict the number of pounds you can expect to lose from each of the most popular bariatric procedures.

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Weight Loss Calculator

General Considerations

In general, patients experience substantial weight loss within the first few years after surgery. However, effective and long-term weight reduction is based on two important factors;

  1. The type of weight loss surgery
  2. How committed you are to changing your life

Surgeons’ technique, age, genetics, gender, starting weight, diabetes, and hypertension are also determining factors in the amount of weight reduction. Of course, lifestyle changes, mental preparation, dietary habits, fitness, and being involved with a support group can contribute to a more successful weight loss journey.

Average Overall Weight Loss Statistics

After bariatric surgery, patients can expect steady weight loss over time. However, each type of bariatric surgery offers patients different results. Our weight loss charts are based on averages, meaning that your weight range may deviate from what is projected.

Bariatric Weight Loss Efficacy Graph Chart Per Surgery

  • Bariatric surgery patients tend to lose 1 to 2 pounds per day for the first 60 to 90 days of their weight loss journey.
  • For popular surgeries like gastric bypass, sleeve gastrectomy, and duodenal switch,  postoperative weight loss ramps up to about 2 to 3 pounds per week between 90 to 180 days.
  • Up until the first year, many patients shed 50-70% of their excess body weight or 15-30% of their total body weight.

Below is a brief outline of long-term weight loss surgery options available for people suffering from obesity and who want to enjoy a healthier life.

Vertical Sleeve Gastrectomy (VSG) Weight Loss Timeline

Sleeve Gastrectomy Weight Loss Timeline Chart

After a Vertical Sleeve Gastrectomy, known as Gastric Sleeve, 80-85% of the patient’s stomach is removed, leaving behind a long, narrow, vertical pouch that can hold about 2-3 oz of food.

It is minimally invasive and has no intestinal bypass, making the VSG one of the most dominant bariatric surgeries in the United States, Canada, and Mexico.

Weight Loss Expectations

By restricting the stomach capacity, increasing sensitivity to satiety hormones, and lowering the production of hunger hormones, gastric sleeve patients can expect to lose almost as much weight as gastric bypass patients while still having a more “normal” diet post-operatively.

Sleeve Gastrectomy Weight Loss Graph

  • 12 months after gastric sleeve, patients can shed 23.4% of their baseline weight or 63% of their excess weight.
  • 3 years patients can expect to lose at least 50% of their excess weight1
  • More than 4 years after their surgery, patients normally lose 17.8% of their total body weight or 43.0% of their excess weight2

Learn More: Sleeve Gastrectomy Weight Loss Timeline

Roux-en-Y Gastric Bypass Weight Loss Timeline

RNY Gastric Bypass Weight Loss Timeline Chart

With a Gastric Bypass or Roux-en-Y Surgery, 90% of the stomach is separated, leaving behind a tiny walnut-sized pouch that bypasses a large portion of the small bowel. The remaining part of the stomach stays in place to build digestive fluids which then reconnects with the bypassed portion of the new stomach pouch.

Weight Loss Expectations

By utilizing two weight loss methods of restriction and malabsorption, the roux-en-y surgery produces sustainable weight loss that lasts longer than the sleeve gastrectomy. Shedding weight is a result of less food consumption and fewer calories getting absorbed into the body. The rate of weight loss is fast and effective in halting obesity-related comorbidities like type 2 diabetes and cardiovascular disease.

Roux-en-Y Bypass Weight Loss Graph

  • In less than a year, gastric bypass patients can lose 60 to 80% of their excess weight on average3
  • After 3 to 5 years, RNY patients have reported 30% of their total body weight reduced4
  • At 10 years, patients maintain a consistent loss of 28.6% of their total body weight5

Learn More:

Mini Gastric Bypass Weight Loss Timeline

Mini Gastric Bypass Surgery (MGB) Weight Loss Timeline Chart

The Mini Gastric Bypass (MGB) has similar techniques to the traditional gastric bypass while only having one anastomosis, or “connection.” This is done by pulling a further down portion of the intestines upward to merge with the new stomach pouch. The MGB is also less invasive and requires less time for surgery and recovery.

Weight Loss Expectations

By reducing the stomach size significantly and limiting calorie absorption, mini-gastric bypass results can be just as effective and sometimes even more so than the regular bypass, with 95% of patients losing more than 50% of excess weight long-term.6

Although this surgical treatment option is not yet FDA-approved in the U.S., it is highly effective, safe, and provides sufficient weight loss results.

Mini Gastric Bypass Weight Loss Graph

  • Two years after the surgery, Patients ordinarily lose 75-85% of excess body weight
  • Five years after the surgery, 70-75% of excess weight loss is maintained7
  • 72.9% Excess weight loss within 10 years

Learn more:

Duodenal Switch (DS) Weight Loss Timeline

Duodenal Switch Surgery BPD-DS Weight Loss Timeline ChartAlso known as the Biliopancreatic Diversion with Duodenal Switch (BPD/DS), the Duodenal Switch Surgery removes 70% of the stomach in the same surgical fashion as the gastric sleeve. The lower intestines are cut and switched with the upper portion of the intestines to speed up digestion and reduce caloric intake substantially.

Weight Loss Expectations

Combining aspects from the gastric sleeve and gastric bypass, the DS is designed for patients who need aggressive weight loss and have exceptionally high BMIs of over 45. While the average weight loss timeline after the duodenal switch has stronger and faster results, it is important to follow strict vitamin and diet guides to avoid not losing enough weight.

Duodenal Switch Surgery Weight Loss Graph

  • Within the first year, 84% of DS patients lose at least 50% of their excess body weight and up to 80%+
  • Over 2 years, patients usually lose 60% to 80% of their excess body weight8
  • 84.2% of these patients maintain this weight loss 3 years after the surgery9

Learn more:

Adjustable Gastric Band (LAP-BAND) Weight Loss Timeline

Adjustable Gastric Band Weight Loss Timeline Chart

The Gastric Band, or Lap-Band, is an adjustable silicone ring that creates a small (1-2 ounce or 15-30cc) pouch at the top of the stomach. This temporarily blocks food, slowing down the digestive process and making the patient feel full faster. Based on the patient, the pouch is tightened or loosened for maximum weight loss success.

Weight Loss Expectations

While it moderately restricts the patient’s food consumption, the lap-band weight loss results are almost half as effective as other procedures. There are very few benefits that the lap band offers compared to other surgeries, but it is less invasive and somewhat reversible.

Adjustable Gastric Band Weight Loss Graph

  • After the 1st year, gastric band patients are expected to lose 20% to 60% of excess body weight
  • By the 5th year after the surgery, 46% of excess weight loss
  • 10 years after surgery, patients maintain 65% of excess weight loss10

Learn more: Gastric Banding Surgery

Gastric Balloon Weight Loss Timeline

Gastric Balloon System Weight Loss Timeline Chart

If a bariatric patient wants to avoid an invasive procedure or needs to lose weight extensively before another surgery, they can opt for a non-surgical Intragastric Balloon. The gastric balloon weight loss system is inserted through the esophagus into the stomach, making it uncomfortable to overeat. Based on the gastric balloon system, such as Spatz and Orbera, it is then deflated and removed endoscopically after 6 to 12 months.

Weight Loss Expectations

While the balloon can have positive side effects, it sheds fewer pounds compared to nearly all other procedures and unfortunately, patients can easily go back to bad habits afterward. Unless the patient is satisfied with their weight loss, we recommend revising to vertical sleeve gastrectomy or RNY gastric bypass surgery.

Gastric Balloon (Spatz) Weight Loss Graph

  • Within 6 months, 30-47% excess weight loss is expected with Orbera when it is removed11
  • By 6 months with Spatz, 26.4% excess weight loss12
  • After 12 months, 48.8% excess weight loss with Spatz when it is removed13

Learn more: Gastric Balloon

How Much Weight Will You Lose?

With bariatric surgery, lifestyle changes have to be made for effective and long-lasting weight loss success. The most significant adjustments for bariatric patients are the new dietary and medical arrangements.

For the first three months, patients will be transitioning from a liquids-only diet to solid foods while readjusting to their new, lower appetites and food consumption. Patients will also have to take vitamin supplements and avoid certain medications based on their needs and doctor’s orders.

While vomiting and constipation can be common, it is essential to eat the recommended levels of food and stay properly hydrated. Patients should notify their specialists of any infected incisions and persistent vomiting.

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