Going through life-changing weight loss surgery, you will need to make many adjustments both before and after surgery, specifically in your gastric sleeve surgery preoperative diet and nutrition.

What is the Purpose of the Pre-Op Diet?

Following nutrition guidelines before gastric sleeve surgery plays a significant role in the outcome of the procedure.

The primary purpose of the pre-op diet is to shrink the liver, which blocks access to the stomach. When the liver reduces in size, it is easy to lift out of the way using retractors and makes the surgical operation a lot less complicated.

Pre-op diet also can benefit patients by taking the first towards healthier eating habits while practicing self-control.

Learn more: What is the purpose of the pre-op diet?

Pre-Op Diet Tips

  • It’s important to consume enough water while on the liquid-only diet.

  • Do NOT take any herbal medications for seven days before surgery.

  • Do NOT take any aspirin, Advil, Nuprin, Aleve or any other non-steroidal anti-inflammatory medication for seven days before surgery. These drugs cause profuse bleeding after surgery. This includes baby aspirin and most arthritis medications. If you are not sure, please check with our Doctors. For a headache or minor pains, you may use Tylenol. You may restart these medications the next day after surgery.

  • You may take needed medications (such as heart or blood pressure medications) with sips of water the morning of surgery as directed by our Doctors.

Prior to Gastric Sleeve Surgery

  • Do NOT smoke 30 days prior to surgery

  • Start taking a probiotic 6 weeks prior to surgery or as soon as possible. You want one that has a minimum of 50 billion units and the more strains the more effective.

Behavior/Lifestyle Changes

  • Discontinue ALL carbonated beverages.

  • Discontinue ALL beverages with caffeine.

  • Cut food into SMALL pieces and practice chewing foods VERY well.

  • Discontinue ALL over the counter Herbal supplements.

  • VERY IMPORTANT: Stop drinking 30 minutes prior to eating and DO NOT drink until 30 minutes after a meal.

  • Begin a routine exercise program (consult with your physician first).

  • LIFELONG HABIT: Do NOT drink with meals.

Overview of the Gastric Sleeve Pre-Op Diet

For most people undergoing gastric sleeve surgery, the amount of time you will need to be on the pre-op diet depends on your BMI. Check BMI requirements to see how long your pre-op diet will take.

The purpose of this diet is to help shrink your liver prior to surgery by depleting stored glycogen.

  • 2 – 3 protein shakes per day -You may purchase these in any health food store or many grocery stores. Please be sure it contains at least 20 grams of protein per serving.  Sugar should be half the grams or less than protein- if you have 20 grams of protein, it should have less than 10 grams of sugar.

  • You can eat as many raw or cooked vegetables as you want (All vegetables are included except peas & corn)

  • 2 servings of 4 oz. of a lean protein (chicken, turkey, fish, lean ground beef, eggs, tofu, beans of any kind except baked or BBQ beans. (you can have more than 4 oz.; this is the minimum per serving)

  • 1 – 2 servings of a healthy fat (salad dressing, olive oil, nuts, avocado, olives)

  • You can add ½ cup of frozen berries or ½ banana to your protein shake

  • You can make your shake with unsweetened vanilla almond milk or coconut milk (no regular milk- too much sugar)

  • Absolutely NO bread, rice, pasta, potatoes, sweet potatoes, yams, cereals, oatmeal, popcorn, refined grains, corn, peas, or sauces with sugar.

  • Weight Loss Magic Soup Recipe – Great Vegetable Soup

Sample Meal Plan for Pre-Op Diet

  • Breakfast: 1 protein shake

  • Mid-morning snack: 1 protein shake

  • Lunch: Raw or cooked vegetables (you can add one TBSP olive oil or butter spray to veggies) and 4 oz.  lean meat. Example: Tilapia with baked broccoli seasoned w/ olive oil and slivered almonds

  • Dinner: Salad with Protein (chicken, fish, egg, etc.), a small amount of no or low sugar dressing (preferably olive oil & vinegar or Lemon)

  • Evening Snack: 1 protein shake (if needed).

  • You may also add 1 TBSP chia seeds to your shakes or take psyllium husk to help you stay satisfied throughout the day.

  • * Patients with higher or lower BMI and/or other medical conditions may be prescribed other dietary prerequisites in addition to the above pre-op diet.

  • * You may at this time drink other drinks as long as they have NO SUGAR

2 Weeks Prior to Gastric Sleeve Surgery

  • Discontinue birth control and Estrogen replacement (HRT) medications.

7 Days Prior to Gastric Sleeve Surgery

  • Specific medications to discontinue: Coumadin, Plavix, Aspirin, Ibuprofen, Motrin, Advil, Nuprin, Aleve or any other non-steroidal anti-inflammatory medication. **Remember this also includes baby aspirin and most arthritis medications. As these can all cause stomach irritation and possibly more bleeding postoperative.

  • Discontinue Vitamin E

  • For a headache or minor pains, you may use Tylenol.

  • Do not take any herbal medications/remedies.

For Diabetes Patients

  • May continue to take medication up to the day of surgery. Be mindful, medications and amounts may change due to diet and weight loss change prior to surgery.

  • MUST consult with their doctors about medication use.

  • MUST check sugar levels at home. If sugar is above 150 call your primary care physician immediately.

2 Days Prior to Gastric Sleeve Surgery – Clear Liquid Diet

  • Clear Liquids Only: Apple or other clear juice without pulp or carbonation.

  • Clear broths: Chicken, Vegetable, or Beef.

  • Water or Flavored Water.

  • Need to have 2 Greek yogurts per day (maybe flavored but no pieces of fruit) – this helps with post healing and providing healthy bacteria in your gut. Plain Greek yogurt is your best option or something similar.

8 Hours Prior to Gastric Sleeve Surgery

  • Absolutely nothing to drink after the midnight preceding surgery or 8 hours prior to your surgery.

  • Absolutely NO medications unless directed by the doctor. (If you have been pre-approved to take any medications by your doctor leading up to surgery, you may take small sips of water for swallowing.)

  • Please bring ALL your prescribed medications (whether you are currently taking them or not) in properly labeled pharmaceutical bottles for documentation during Pre-Op testing. Do NOT take any medications after surgery until you have consulted with the doctor(s) and gotten approval.

We hope that this information on the gastric sleeve surgery preoperative diet proves useful to you. If you have any further questions, you are welcome to contact us at any time.

Guide to Gastric Sleeve Surgery: