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From liquids to solids: What to expect from the gastric sleeve pre-op and post-op diet

Gastric sleeve diet

Gastric sleeve surgery, also called vertical sleeve gastrectomy, is one of the most popular weight-loss operations I offer today. It’s safe, minimally invasive, and most importantly - it’s effective. However, gastric sleeve surgery is a considerable commitment and involves a lot of lifestyle changes. One of the main concerns patients have about gastric sleeve deals with how much their diet will change. Below, we go over the pre-op and post-op diet for the gastric sleeve surgery and what to expect throughout the whole process.

The importance of the pre-op diet

The pre-op diet helps shed fat from the abdomen and shrink the liver for better visualization and a smoother surgery. The liver sits right on top of the stomach, so we need to be able to get it out of the way to in order to perform the surgery safely. It’s also imperative to reduce the fat around the stomach so that it’s easier to dissect and get staple lines formed properly.

In other words, the pre-op diet helps surgeries go smoother and safer. A smoother surgery means less time under anesthesia which can lower the risk of post-op nausea and vomiting, decrease the risk of developing blood clots in the legs, and potentially lower the risk of leakage from better formed staple lines.

The pre-op diet: it’s all about nutrition

Some surgeons put people on a two-week liquid diet to force weight loss before gastric sleeve surgery. My philosophy is that patients should get into the game early and make the changes necessary to lose weight on their own. I provide a manual and educate patients during their consultation about making better food choices and doing things that will prepare them for their new lifestyle down the road.

I want my patients eating more lean proteins, more fruits and vegetables, drinking a lot of water, and walking every day. I want them to get into the “mode” of losing weight and leading a healthier life-style. I want them properly nourished and healthier coming into surgery, not starving their body right before major surgery. The last thing you want is muscle wasting right before surgery when your body needs adequate stores for wound healing.

In short, I don’t force patients to do a two-week liquid diet. Instead, I try to educate them as to why it’s crucial to lose weight pre-op and be in a healthier frame of mind. The goal is to lose 10 lbs or more preceding surgery so that they are lighter, healthier and in a better frame of mind. However, I do put all patients on a liquid protein diet 2 days before surgery to clean out their intestines and shrink the liver (liver can hold up to 2 days worth of food) so there is more room to operate.

Every patient has a pre-op class two weeks before surgery, but by that point, they should’ve already been doing the work preparing themselves for surgery. This class is to hone in on the diet requirements for post-op.

Post-Op Diet: Why it’s important

Post-op dieting is primarily about protecting patients from a complication called a leak. A lot of people think post-op dieting is for them to get used to certain foods again and for the stomach to get used to things. However, the post-op diet ensures that the stomach is not overstretched while it is healing.

In the first few weeks after gastric sleeve surgery, the stomach is held together with three rows of staples. Those staples are similar to the staples you’d staple paper together with. If you pull that paper hard enough apart, you pull the paper right off the staples. The same goes for the stomach tissue and staples. If you stretch the stomach wide enough, you could pull it off of its staples. It’s hard to do because there are three rows of staples, but it is possible. Therefore, we don’t want people eating solid foods that could get stuck and cause vomiting. Vomiting puts a lot of pressure in the stomach pouch and needs to be avoided until the stomach is completely healed 3-4 weeks out from surgery.

Once the stomach is healed, the scar tissue that the body puts over the staples is much more durable than the staples themselves. By that point, the stomach is as good as new and can tolerate solid foods, vomiting, etc.

The three stages of the post-op diet

After a gastric sleeve operation, patients go through three stages before they can eat solid foods again. During each phase of the post-op diet, patients are required to drink 64 oz. of fluid.

The only thing that changes is the consistency of the protein you are eating to keep you nourished.

Stage 1: Thin protein

In the first ten days, protein is consumed in the form of a powder that dissolves in liquids, so it’s called thin protein.

Stage 2: Thicker shakes.

During the second stage, protein comes in the form of a protein shake, so it’s heavier, but it’s not so heavy that it’s going to get hung or stretch the stomach.

Stage 3: Soft proteins

During this stage, patients eat soft proteins like eggs, yogurt, tuna, and cottage cheese for about two weeks.

Altogether, it takes about five-weeks before patients are able to eat solid protein again without the risks associated with vomiting or stretching the stomach.

As you can see, gastric sleeve surgery requires a lot of commitment and a lot of change. We do everything we can to prepare our patients for these changes, and we are here to answer any questions or concerns they may have along the way. We offer dietary counseling throughout the journey via the surgeon, nurse practitioner, and our registered dietitians. We also have comprehensive guides so that patients have the tools they need to be successful every step of the way.


Contact Nashville Weight Loss Solutions for more information about our weight loss options.

Are you dieting and exercising on your own, but still not getting the results you want? Nashville Weight Loss Solutions offers a comprehensive range of proven weight loss programs to help, whether you need to lose 20 pounds or 200. Contact our office today to schedule a consultation!

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