How Much Weight Will I Lose With Gastric Bypass Surgery

Gastric Bypass Surgery is one of the most well-known and widely used weight-loss surgeries available. Not only is it FDA approved, but it was also at one point the “gold-standard” of bariatric surgery. The gastric bypass (RNY) works by creating a pouch from the stomach (becoming the new stomach) and reroutes the small intestine to the new stomach pouch.

Gastric Bypass Surgery RNY Schematic

Although extremely effective, the gastric bypass offers different results – but here are the average number of pounds you can expect to shed with gastric bypass surgery.

What are the Factors That Affect How Much Weight I Lose?

The amount of weight you will lose with gastric bypass surgery depends on a number of factors. These factors include nutrition, exercise, lifestyle, and total commitment to changing old habits.

  • Nutrition and diet
  • Exercise and physical activity
  • Lifestyle changes
  • Bariatric vitamins
  • Commitment to change old habits
  • Age
  • Body size and type
  • Genetics

How Much Weight Will I Lose With Gastric Bypass Surgery

  • 3 Months: 35% Expected Weight Loss
  • 6 Months: 55% Expected Weight Loss
  • 12 Months: 72% Expected Weight Loss
  • 18 Months: 78% Expected Weight Loss

How Much Weight Will I Lose with Gastric Bypass Surgery RNY

Other Variables Impacting Weight Loss

The surgeon experience and procedure quality make up the surgical aspect and success rate of the surgery as well. This means the bariatric surgeon’s knowledge, technique, and expertise can make your weight loss results differ.

As an example, how well the surgeon makes the new pouch and how much restriction it creates is a major factor in losing weight and maintaining it. Apart from the surgeon and team, there are more factors after surgery that can affect the success rate of gastric bypass and its single-loop version mini gastric bypass surgery.

Let’s suppose you do everything correctly after gastric bypass surgery or mini gastric bypass surgery. You’ve changed your diet (gastric bypass makes some dietary changes, which is why the gastric bypass creates more weight loss than most other procedures) that you are regularly exercising and you try to sit less and be more active. How long will you stay motivated when everything is said and done?

Weight Loss Calculator With Gastric Bypass

In order to find out how much weight patients will lose, let’s look at the average weight loss of the surgical procedure of the gastric bypass surgery in Tijuana Mexico. Since different people have different heights and weights, they have different BMI, or body mass index.

We cannot measure the weight loss expected in total pounds, although patients can calculate their expected weight loss themselves. Someone who is 6 feet 2 inches and 400 pounds will lose another weight than the one that is 5 feet 4 inches and 220 pounds. But these two patients will lose a similar percentage of their excess weight.

Gastric Bypass Expected Weight Loss

Gastric Bypass Weight Loss Calculator

You will need some numbers to start calculating the expected weight loss. Follow Steps 1 through 4 and you should have expected weight loss calculated in minutes.

1. What is Your Ideal Weight?

There are some common ways to calculate ideal weight. This calculator shows your ideal weight for all the different methods for determining that number. Usually, you can use a larger number, which is usually the number of body mass indexes.

2. How Much Excess Weight Should You Lose?

Current Weight – Ideal Weight = Overweight

3. How to Calculate Expected Weight Loss:

Excess weight x .70 = Expected Weight Loss

4. How to Calculate Your New Weight:

Current Weight – Expected Weight Loss = New Weight After Operation

Regardless of the weight loss you choose, you may expect to lose a certain amount of weight from the bariatric surgery in Tijuana Mexico. This calculator will tell you how much weight you can expect to lose with gastric bypass and each bariatric procedure. Also to determine what you can expect to weigh two years after surgery.

Calculations are based on average weight loss per process. To lose the average weight, you will need to follow the preoperative and postoperative guidelines of your surgeon.

Diet and Exercise

Long-term diet and exercise changes along with other habits changes can result in weight loss that exceeds the average values used in these calculations.

Keep in mind that 70% is the average weight loss from past gastric bypass patients. There are people who lose less and others who lose much more. In the end, the success of a gastric bypass just sets the appropriate expectations, makes the decision to change your habits and adheres to those decisions.


If your number looks lower than expected, do not be feel defeated. People are surprised that they can not expect to go from 250 kilograms (551 pounds) to 120 kilograms (264 pounds) with bypass surgery alone. Gastric bypass is not a quick fix but will reduce your weight to a slightly easier handling. When weight falls, it becomes easier to exercise, stay longer, enjoy life and continue to lose weight.

The hardest part is losing the first 50 kilograms or 110 pounds of weight. When you begin to notice the results, this will motivate you to lose more, eat healthier, boast about your friends, and show your amazing progress. Good luck!

Mexico Bariatric Center