• You must prepare your body before surgery, this pre-op diet is to shrink the liver; also to decrease blood lipids and prevent post surgical complications.
  • Start 10-20 Days Prior to Surgery (**Depends on BMI, see last page)
  • Do not smoke.
  • Use a prepared canned or powdered protein drink (prefer a fat free and carb free one). You may purchase these in any health food store or many grocery stores.
  • Please be sure it contains at least 15 grams of protein per serving. You can make your shake mixing half water and half unsweetened vanilla almond milk,  coconut milk or skim milk.


  • Breakfast: 1 protein drink
  • Lunch: 1 protein drink
  • Dinner: Salad with Protein (chicken, fish, egg, etc.), small amount of low-fat or fat-free dressing, or olive oil and vinegar.
  • Evening Snack: 1 protein drink (if needed).

* You can eat one more portion of raw or cooked vegetables if you feel hungry.

  • Discontinue vitamins, Aspirin (unless it is baby-aspirin prescribed for heart condition), Ibuprofen, Motrin, Advil, Nuprin, Aleve or any other non-steroidal anti-inflammatory medication. This includes most arthritis medications. These medications can cause unnecessary bleeding after surgery. (If you are not sure,
    please check with our doctors.)
  • For headache or minor pains you may use Tylenol.
  • Do not take any herbal medications/remedies.

CLEAR LIQUID DIET (After the pre-operatory diet and before surgery)

**Few days Prior to Surgery (**Depends on BMI, see last page)

In a clear liquid diet you can only have transparent liquids (liquids you can see through); this kind of liquids stays liquid at a normal temperature. Some examples of these liquids are:

  • Fruit juices (apple, grape, cranberry, etc.) mixed with water
  • Non-fat broths: chicken, beef or fish. (Just the broth)
  • Jell-O
  • Tea
  • Flavored Water
  • Gatorade
  • Popsicle (Water base; not milk)

You also should take a Whey protein Supplement, no carbohydrates and non fat. And mix it with water. You can have from 1 to 3 servings of this protein per day.

*Milk or dairy is not allowed on this diet.

Complete bowel prep by taking a laxative of your preference on the 3rd day prior to surgery.

8 Hours Prior to Surgery

Absolutely nothing to drink after the midnight preceding surgery, or 8 hours prior to your surgery. (Your stomach has to be empty)

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.

NOTE: High blood pressure, anti-depressives, thyroid hormone substitutes medications SHOULD NOT be suspended.

Get more suggestions in the PDF file below
Download PDF File with Complete Diet

Pre-Op Complete Diet
Open and download PDF file with complete Pre-Op Bariatric Surgery Information.
Click here to download file
Download PDF File Complete Manual

Medications and Surgical Symptoms
Includes some details about pre op medications and possible post surgical symptoms.
Click here to download file

How many days should I follow the PRE-OPERATORY & CLEAR LIQUID diet?

If BMI is 30-40. Follow the diet 10 days Start the pre-Operatory diet 10 days prior to surgery. And start the Clear Liquid diet 3 days prior to surgery. If BMI is 40-45. Follow the diet 14 days Start the pre-Operatory diet 14 days prior to surgery. And start the Clear Liquid diet 5 days prior to surgery. If BMI is 46-60. Follow the diet 15 days Start the pre-Operatory diet 15 days prior to surgery. And start the Clear Liquid diet 8 days prior to surgery. If BMI is >60. Follow the diet 20 days Start the pre-Operatory diet 20 days prior to surgery. And start the Clear Liquid diet 10 days prior to surgery. *Patients going through Bypass or Duodenal Switch surgery, 3 days prior to surgery please take one (gentle) laxative, only one time (any brand).


We suggest you to take along some gas X strips, some packs of gauze, a roll of medical tape, pack lightly and take a comfortable pair of walking shoes. Remember to keep your fingernails trimmed or the doctors might have to trim one of the index finger nails short to accommodate checking your oxygen levels during surgery. (And at least that fingernail has to be without nail polish.)

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