A Guide to the Gastric Sleeve Pre-Op Diet

You’re considering gastric sleeve (also known as sleeve gastrectomy) surgery, but you have some questions about the pre-op diet. What is it, and why is it important? Are there any side effects? How will the diet impact any medications that you may be taking?

Let’s walk through these questions together. By the end of this blog, you’ll have a good sense of what to expect on the pre-op gastric sleeve diet, as well as why this diet is so important to your long-term weight loss goals.

What Is the Pre-Op Diet for Gastric Sleeve Surgery?

In the weeks before you undergo sleeve gastrectomy surgery, you will need to adhere to a strict pre-op diet. This diet is important for three reasons.

First, this diet will help to shrink your liver. This is essential because the liver sits on top of the stomach, and an enlarged fatty liver can make it harder for the bariatric surgeon to get underneath the liver to operate on the patient’s stomach; which can increase the risk of complications (this is especially important if the patient suffers from fatty liver disease). At the BMCC, we take your health, your safety, and the success of your weight loss surgery very seriously. While complications are very rare, it is also important that you do everything in your power to reduce the already small risk. 

Second, this diet will help you to start training good habits when it comes to diet. A short-term diet, coupled with an achievable goal, can help you to start to ingrain good habits around eating and drinking. This is important because so much of your success on your weight loss journey will come down to how well you stick to the post-op diet and exercise regime that our team will work with you to develop.

Third, this diet is high in protein, which is necessary for wound healing. Adhering to this pre-op diet can improve your recovery time substantially.

For these reasons, this diet is a requirement; and your weight loss surgery cannot proceed if you have not adhered to it.

Gastric Sleeve Pre-Op Diet Part 1: 3 Weeks Before Surgery

3 weeks before your surgery, you will need to adopt a new diet. Here’s what it will entail:

Dos:

• Eat/drink more protein (lean meats such as fish and turkey, shakes that are low in sugar, etc.). 
• Eat non-starchy vegetables. 
• Eat healthy, unsaturated fats (i.e. olive oil, nuts, olives, avocado, etc.). 
• Stay hydrated (64oz of water per day)

Don’ts:

• Eat dairy like yogurt, milk, or cheese.
• Eat refined carbs (bread, pasta, etc.).
• Drink alcohol or sugary drinks.
• Smoke (THC, nicotine, or otherwise).

Gastric Sleeve Pre-Op Diet Part 2: 1 Week Before Surgery

One week before surgery, you will need to transition to a full liquid bariatric diet.

This diet should include:

• Vitamin-reinforced protein shakes (you’ll need to consume 80-100 grams of protein per day)
• Low-sodium broth-based soups
• Water (64 oz or more per day)
• Flavored water (sugar-free)
• Tea (unsweetened)
• Jell-O (sugar free)
• Popsicles (sugar free)
• Fiber supplements (to prevent constipation)

You will need to avoid:

• Sugary drinks
• Carbonated beverages
• Caffeine
• Alcohol

Gastric Sleeve Pre-Op Diet Part 3: The Day of Surgery

The day of your surgery, about 4 hours before your surgery, you will be asked to drink 12 ounces of Gatorade or another electrolyte solution that can enhance your recovery. After this, you should not eat or drink anything other than a small sip of clear liquids to take medications. This is to prevent food or liquid in the stomach, which could increase the risk of anesthesia complications. If you do eat or drink something within 4 hours of your surgery, then your surgery will need to be rescheduled out of concern for your safety.

Potential Symptoms of a Liquid Diet

During the first 2-3 days of the liquid diet, it’s common to experience the following symptoms:

• Hunger pangs
• Fatigue
• Headaches
• Nausea
• Constipation
• Loose stool (possibly including diarrhea)
• Irritability or mood swings

If you experience these symptoms, please know that they are completely normal. They are a temporary reaction to your body getting fewer calories and carbohydrates than it is used to, and they should subside within 2-3 days. Drinking at least 64oz of water per day can also alleviate many of these symptoms.

It is important to note, however, that if you have baseline chronic kidney disease or renal failure, then this diet can put stress on your kidneys. For this reason, it is very important that you communicate any kidney conditions with your bariatric surgeon before your diet begins so that we can work with you to adjust the diet if necessary in order to protect your kidneys.

What About Medications?

It is very important that you communicate with your bariatric surgeon about any medications that you are on. Some of these can lead to complications during surgery or problems with the pre-op diet for gastric sleeve surgery.

In general, you will have to stop taking all of the following medications in the lead-up to surgery:

• Hormone replacement medications (ex. estrogen; birth control pill, patch, or ring)
• Non-steroidal anti-inflammatory drugs (NSAIDS) (stop 2 weeks before surgery)
• Blood-thinning medications (ask your surgeon when to stop taking these)
• Herbal medication

If you are diabetic, contact your prescribing physician to discuss managing your diabetes medication during these 3 weeks. Your doctor may decrease your insulin for this period.

Taking the Next Step On Your Weight Loss Journey

If you’re ready to take the next step on your weight loss journey or have any other questions, we encourage you to schedule a bariatric assessment with us or just give our friendly staff a call. Our team includes a bariatric dietitian who will help you to optimize your nutritional intake both before and after surgery. We care deeply for our patients and our entire team will be with you on every step of your journey both pre- and post-surgery, and we invest heavily in your education to give you nothing but the best outcome.

Our patients routinely say that surgery was the best decision they ever made.

“We cannot imagine another Doctor or Practice with whom this process could have been so wonderfully orchestrated…. Dr. Long and his staff are the kindest, most loving, and supportive group of individuals we have ever could have met. Each person has contributed to our success, each and every one.”—Keri and Chris Sexton, gastric sleeve patients.

If you’re suffering, don’t wait. Contact our Denver office today.