Patients often want to know exactly how much weight they will lose from gastric sleeve surgery. The answer changes for every patient. But there are some easy ways to calculate your expected weight loss. Having proper expectations for how much weight you can expect to lose, assuming you follow the after surgery guidelines, is an important factor when considering your overall happiness with having had surgery.
How Much Weight Will I Lose?
The amount of weight you will lose depends on a number of factors. These factors include, diet, exercise, lifestyle, and your overall commitment to changing old habits. The size that your surgeon makes your new sleeve can make a difference in overall weight loss.
Let’s assume you do everything right. You’ve changed your diet and you’ve created new healthy habits. You exercise on a regular basis. On average people lose 60% (Stegemann, Obesity Action Coalition, 2012) of their excess weight with gastric sleeve surgery. This includes people who have followed their post operative guidelines and people who have not.
If you follow the guidelines, change bad habits, replace them with new healthy habits, then you can expect to lose more than 60% of your excess weight.
Average Weight Loss With Gastric Sleeve Surgery
Before we make any calculations, let’s look at the average weight loss from gastric sleeve surgery. Because different people have different heights and weights and therefore different body mass index’s, we cannot use pounds alone to measure expected weight loss. Someone who is 6 foot 2 and 400 lbs will lose a different amount of weight than someone who is 5 foot 4 and 220 lbs. But both of these patients will lose a similar percent of their excess weight.
Example Weight Loss
Patient 1 is 6 foot 2 and 400 lbs:
- Patient 1’s ideal weight is 194.7 lbs.
- Patient 1 has 205.3 lbs of excess weight.
- He loses 60% of his excess weight, 123 lbs.
- His new weight is 277 lbs, 2 years after surgery.
Patient 2 is 5 foot 4 and 250 lbs.
- Patient 2’s ideal weight is 145.6 lbs.
- Patient 2 has 104.4 lbs of excess weight.
- She loses 60% of her excess weight, 62 lbs.
- Her new weight is 188 lbs, 2 years after surgery.
You can see how patient 1 lost 123 lbs and patient 2 lost 62 lbs but both of them lost the same percent of their excess weight. This is why we measure average weight loss after weight loss surgery as a percentage of excess weight. Using your excess weight calculation, we can then find your expected weight loss.
On average gastric sleeve patients lose 60% (Stegemann, Obesity Action Coalition, 2012) of their excess weight. We will use that number for the calculations below.
Calculate Your Expected Weight Loss From Gastric Sleeve
You will need a few numbers to get started calculating your expected weight loss. Follow steps 1 through 4 and you should have your expected weight loss calculated in just a few minutes.
1. What is your ideal weight?
There are a few common ways to calculate ideal weight. This calculator shows your ideal weight for all of the different methods to determine this number. I typically use the largest number, which is usually the high body mass index number.
2. How much excess weight do you have to lose?
Current Weight – Ideal Weight = Excess Weight
3. How to calculate your expected weight loss:
Excess Weight x .60 = Expected Weight Loss
4. How to calculate your new weight:
Current Weight – Expected Weight Loss = New Weight After Surgery
Use Our Calculator
Regardless of which weight loss surgery you choose, you can expect to lose a certain amount of weight from bariatric surgery. This calculator will tell you how much weight you can expect to lose from each bariatric procedure and what you can expect to weigh two years after surgery.
The calculations are based on average weight loss per procedure. To lose the average amount of weight, you’ll need to follow your surgeon’s pre-operative and post-operative guidelines.
Long term diet and exercise changes along with other habit changes can lead to weight loss that exceeds the averages used in these calculations.
Keep In Mind
Keep in mind that 60% is an average. There are people who lose less and some that lose much more. Ultimately, success from gastric sleeve surgery comes from setting the proper expectations, making a decision to change your habits and sticking to that decision.
If your number seems lower than expected, do not get upset. People are surprised that they cannot expect to go from 250 lbs down to 120 lbs from surgery alone. No single weight loss procedure is a magic bullet, but surgery will get your weight down to something more manageable. Once your weight drops, it becomes easier to exercise, stay on your feet longer, enjoy life and continue to lose more weight.
If you’d like to see what the top 20% of gastric sleeve patients can expect to lose, use this calculator.
The hardest part is losing the first 50 lbs of weight. Once you start to notice results you will be motivated to lose more, eat healthier, brag to your friends, and show off your amazing progress. Our Big Gastric Sleeve Diet Guide will put you on the path to success. Don’t forget to check out our article that we recommend all new patients read before bariatric surgery. Best of luck!