Your Fastest Guide To Gastric Bypass

I had gastric bypass in 2016, after reaching the upper limits of how much weight gain I could handle. Yet, it wasn’t my first choice, because it felt very invasive and incredibly drastic.

But, I could feel that I was at the end of my rope, and really needed help. So, when I was doing my research, I had so many of the same questions that you have.

I want to share what I know, as someone who has gone through the fire.

What is Gastric Bypass?

Roux En Y, also called Gastric bypass, is a weight loss, or bariatric, surgery where the top of the natural stomach is removed and a limb from the small intestine is attached, in order to bypass a portion of the small intestine.

What Does Gastric Bypass Do?

Gastric bypass creates extreme weight loss through restricting the amount of food a patient can eat, and malabsorption of those calories because the food doesn’t travel through the entire digestive system.

So, the terms restriction and malabsorption are used frequently when talking about weight loss from gastric bypass.

What is gastric bypass?
What is gastric bypass?


Once the pouch is removed from the natural stomach, it shrinks because nothing is getting introduced to it.

But it still creates all the stomach acid and the enzymes that are necessary to the digestive process.

It’s still doing the same things as before surgery, only it isn’t breaking down the food anymore.

How does gastric bypass help you lose weight?

A small pouch is created at the top portion of the natural stomach when it is cut from the rest of the stomach.

The pouch created after gastric bypass is only about 1 cup or 15 ml.

As this pouch is so small, a gastric bypass patient will feel painful restriction when they eat too much. By learning how to restrict portion size through this way, the patient can decrease the amount of calories they are eating.

The food travels from the newly created pouch through a limb created from the small intestine, bypassing a portion of the normal digestive system.

In bypassing, the calories eaten aren’t absorbed 100%, meaning the body can’t turn all of that food into excess fat. Although, in this 2017 review published by the National Library of Medicine, the findings were that malabsorption actually plays a minimal role in weight loss after surgery (about 11%).

That should ease some big fears some may have over the downsides malabsorption could have for their future.

How much weight can you lose with gastric bypass?

Gastric bypass patients can lose anywhere from 70-80% of the excess weight they need to lose. This is one reason it is the gold-standard in weight loss surgery.

What does that look like for you?

By looking at the chart below, it’s easy to see that the potential for excess weight loss is higher with gastric bypass.

So, for people who have a lot of excess weight, gastric bypass makes the most sense. For those with smaller amounts of excess weight, the lap band makes more sense.

I’m just using the basic BMI goal weight of 150 lbs here, but substitute your own numbers for a more accurate estimate.

Starting Weight at SurgeryBMI Goal WeightHow Much Excess to LoseGastric Bypass (RNY) 70-80% weight loss expectedGastric Sleeve 50-70% weight loss expected Lap Band 50% weight loss expected
450 lbs150 lbs(450-150)= 300 lbs(300*70%) = 210 lbs
(300*80%) = 240 lbs
(300*50%) = 150 lbs
(300*70%) = 210 lbs
(300*50%)= 150lbs
400 lbs150 lbs(400-150)= 250 lbs(250*70%) = 175 lbs
(250*80%) = 200 lbs
(250*50%) = 125 lbs
(250*70%) = 175 lbs
(250*50%)= 125lbs
350 lbs150 lbs(350-150)= 200 lbs(200*70%) = 140 lbs
(200*80%) = 160 lbs
(200*50%) = 100 lbs
(200*70%) = 160 lbs
(200*50%)= 100lbs
300 lbs 150 lbs(300-150) = 150 lbs(150*70%) = 105 lbs
(150*80%) = 120 lbs
(150*50%) = 75 lbs
(150*70%) = 105 lbs
(150*50%)= 75lbs
250 lbs150 lbs(250-150) = 100 lbs(100*70%) = 70 lbs
(100*80%) = 80 lbs
(100*70%) = 70 lbs
(100*80%) = 80 lbs
(100*50%) = 50lbs
An example of how much weight someone can lose with weight loss surgery

Who qualifies for gastric bypass?

Gastric bypass surgery has some qualifying factors or barriers to entry.

To get gastric bypass, most people must have a BMI of 35-40 and at least one co-morbidity. A co-morbidity is an obesity related disease, such as type 2 diabetes or hypertension.

This qualification is in place because this is a major, life-changing surgery. It is not a quick fix, or an easy way to drop a few pounds. This is to help those with extreme weight loss needs.

A Real Example of How Much Weight Can Be Lost With Gastric Bypass

I started out at 330+ pounds before I started the gastric bypass program.

In order to do the surgery, I had to lose about 10 lbs, so that can be counted or left out of the overall weight loss depending on your preference.

My surgery weight was 312 lbs. Based on the chart above, I expected to lose around 105 to 120 lbs. That meant I expected to be around 192 lbs.

I actually lost WAY more than that, through adding in HIIT exercises. My weight loss total was closer to 54% of my OVERALL body weight! Maybe I’m an outlier, but guess what? It means it’s a possibility.

I’m 192 lbs NOW, after 2 pregnancies. I was 145 lbs at my lowest weight. And that was actually too small, so I had to change the way I ate to gain back some weight. I really like 155 lbs for my 5’6 female frame. That’s what’s right for me.

About 150 lbs after Gastric Bypass

Will I have Scars After Gastric Bypass?

There are about 5 scars on the abdomen when gastric bypass is done laparoscopically.

They are done in a shape resembling a star. All these year later, I can only see two, maybe 3.

The others have faded so much I can barely remember where they were.

The biggest scar is on the left side of my abdomen, next to my belly button. I call it my “Shark Bite”.

It’s where the actual work was done, where the other scars are where the laparoscopic tools were inserted to blow up the abdomen cavity.

I don’t remember this, as I was under anesthesia, but I remember being concerned about scars. It’s not a big deal, and I’m happy to wear a two piece to show them off.

How Long Does Recovery After Surgery Take?

Recovery from surgery can be anywhere from 1 week to 6 weeks.

Gastric Bypass is a major surgery, so the recovery time after gastric bypass is pretty substantial, too. Everyone is different, so the range is pretty large.

I took 6 weeks to recover, but I also milked some of that time, if I’m completely honest.

After about 4 weeks I could have easily gone back to my office desk job. I was tired, but I wasn’t bedridden.

What is Recovery Like After Surgery?

This is major abdominal surgery, so bending and standing up were difficult.

The first few days it was difficult to walk from the couch to the bathroom. But after that, I could move fine. And I should have moved sooner.

Moving sooner makes recovery faster. Sleeping in a reclining position was the best thing ever. The position was the most comfortable, and I was able to stand up easier.

Eating was completely something new.

The first phase was liquids, then soft foods, then semi-soft, and then finally normal crunchy foods.

Related: How To Get Rid Of The Foamies After Gastric Bypass

How Much Can You Eat After Surgery?

The pouch can only hold about an ounce at a time immediately after surgery.

Once it is healed, the pouch can fit about a cup full of food at once – even 5 years out. But right after surgery, the pouch is swollen and inflamed. That’s why there is the liquids phase.

The pouch can’t handle anything more than liquids at that point.

As the pouch heals, it can hold more food. I remember thinking I’d stretched out my pouch as it healed, because all of a sudden I could eat a lot more than just an ounce. It freaked me out. But it’s normal, and the goal here.

How Long Is the Liquids Phase After Surgery?

The liquids phase doesn’t last very long, just one to two weeks.

Then you can start introducing soft foods to the healing pouch. The liquids phase can be hard, mentally, though. I think my biggest regrets happened while I was in the liquid stage.

Also, some of my most enlightening moments about my relationship to food.

If I had to go on a liquids diet now, I would be able to just fine. But those first few weeks after surgery were literal torture to my brain, because all I wanted was to chew on SOMETHING.

Work on non-food related coping mechanisms to help you through the liquids phase – check out my YouTube video on the liquids phase.

How Do I Exercise Right After Gastric Bypass Surgery?

The best exercise right after gastric bypass is walking.

As you’re losing the weight so fast, the body is already exhausted. First of all, the calorie intake is severely reduced so you don’t have as much energy coming into the body.

Second, your body is using up the fat stores and that’s taking energy to convert, as well. And on top of that, you’re healing from major surgery.

So, I had a plan to join a roller derby team after my surgery. My surgery was in February, and try-outs were in March. I missed the try-outs.

I could barely walk around the block at that point. But! By May of the same year, I tried out, and made the team. So, maybe you don’t hard core exercise the first month after surgery.

But maybe you do the second, or the third. The healing time isn’t THAT long.

Hey, I may have made plenty of excuses for delaying the inevitable, but once I got moving I LOVED IT!

I hope you will, too.

Happy Weight Loss!


For most of my life I was overweight. In my 30s, I became morbidly obese, tipping the scales over 330 pounds. After trying and failing at every diet, I decided to get gastric bypass RNY weight loss surgery. Since 2016 I have been living a much healthier life, I hit my weight loss goals, but more importantly, understand weight loss now. I am determined to share what I now know.

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