Gastric Bypass Weight Loss Chart

Written by Bailey Opsal, RN and medically reviewed by Dr. Stephen Boyce, MD

So you’re interested in gastric bypass surgery for weight loss – that’s amazing! Gastric bypass surgery is one of the best ways to achieve sustained weight loss, even years after surgery. During surgery, your surgeon bypasses part of your stomach and small intestines so less food can be absorbed and you feel fuller faster. When compared to other weight-loss surgeries, gastric bypass results in better long-term weight loss, less risk of later reoperation, and more comorbidity remission.

Gastric Bypass Weight Loss Chart

After gastric bypass surgery, weight loss is measured as a percentage of “excess weight” or EWL. Think of it this way – 50 lbs can be a significant amount of weight loss for a 175lb patient. But if you’re 450lbs, the 50lb weight loss isn’t as substantial. That’s why we look at weight loss as a percentage of excess weight – to give better context. 

Excess weight is determined by finding your current weight minus your “ideal weight”. Find out your ideal weight here

Most patients rapidly lose and sustain weight loss for at least 2-3 years after surgery. The gastric bypass weight loss chart below shows you what to expect.

Data points:

3 months after surgery: 30% of EWL

6 months after surgery: 50% of EWL

12 months after surgery: 65% of EWL

3-5 years after surgery: around 70% or more EWL

Gastric Bypass Weight Loss Chart Bari Life

Average Weight Loss After Gastric Bypass

After gastric bypass surgery, weight loss can vary. Most patients can expect to lose about 70% of their excess weight after surgery. Take a look at the gastric bypass weight loss chart above to get a good idea of when to expect changes.

Something to keep in mind is how gastric bypass surgery can support your health in different ways, apart from just weight loss. While it does support sustained weight loss, surgery also improves comorbidities, such as diabetes, heart disease, or high blood pressure. These side effects can make prominent positive changes on your health and should be celebrated, just as weight loss.

Gastric Bypass Weight Loss Chart Bari Life

Factors That Affect Weight Loss After Gastric Bypass

While the surgery itself can help boost your weight loss, there are some things that can play a role in your total weight loss. Let’s look at them.

Weight before surgery 

Your weight before surgery can impact how much weight you lose after surgery. Patients with a higher BMI at the start tend to lose more weight because they have more to lose.

Overall health

How healthy you are overall can impact how much weight you may lose after gastric bypass surgery. Without some level of health, it’s hard for patients to recover well after surgery and follow post-surgical guidelines. That’s why surgeons request you lose weight before surgery. It supports your health and improves your post-surgical results.

Ability to exercise

Whether or not you’re able to exercise also plays a big role in weight loss. If you’re sedentary or immobile, you can’t move your body in your daily life, let alone exercise. See your doctor if there are any factors getting in the way of your ability to exercise, such as injury. 

Your commitment after surgery

Motivation and commitment to post-surgical care plays a huge role in the success of your surgery. If you don’t change your habits after surgery, don’t expect any changes in your health! This is why your surgeon gives you follow-up care recommendations and has you follow a post-surgical diet. Adhering to these recommendations supports your success. 

Social support

Did you know support from your social circle can impact your success after surgery? Think of it this way. If your family is knowledgeable about what to expect after surgery, they can help support you in times of struggle. If not, they can lead you astray. It’s important to keep your family and friends in the loop on your health and post-surgical guidelines so that they can support you.

Gastric Bypass Weight Loss Chart Bari Life

Keys To Success After Gastric Bypass Surgery

Commit to your new lifestyle

You made a brave choice and healthy commitment when you decided to have gastric bypass surgery. One of the keys to your success after surgery is honoring that commitment you made to yourself. Follow your post-operative recommendations and remind yourself why you started this journey when things get tough. It can also help to look again at the gastric bypass weight loss chart as a reminder of the results you can expect when you follow your surgeon’s guidelines.


Following your surgeon’s post-surgical diet recommendations is essential. Because of the change to your digestive system, a new way of eating is necessary so you get all the nutrients you need. This is the basis of your new diet. Also, your diet changes the farther out from surgery you are. Here’s a brief overview of what to expect. 

Support groups

Join a bariatric surgery support group to connect with others and help maintain your lifestyle. While family and friends can be very supportive, sometimes you need to talk with someone who’s been where you are or can relate to you on a deeper level. This is where joining a support group comes in – you get personalized support from “I’ve been there” people. 

Support your body with supplements

After surgery, your body can’t get all the nutrients and vitamins it needs from food alone. Without some basic supplements, your weight loss can stall. 

Gastric Bypass Weight Loss Chart Bari Life

Supplements For Gastric Bypass Surgery

Gastric bypass is a great option to promote significant weight loss and improve your health. As you learned from the gastric bypass weight loss chart, gastric bypass can be significant if you follow your surgeon’s recommendations after surgery. But this is just a great start – there are other steps you can take.

Supplementation is easy to do and helps you stay healthy after surgery while also promoting weight loss. But unfortunately, not all multivitamins are made the same. Because your body has specific needs after surgery, you need a multivitamin made specifically for you. 

This is why BariLife dedicated a whole line of supplements specifically for the post-bariatric patient. Our Complete Bariatric Multivitamin Tablets include everything your body needs after surgery – no other vitamins necessary. Check them out here.

Gastric Bypass Weight Loss Chart Bari Life


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