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Pre-Op Diet

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    Understanding the Pre-Op Diet

    The pre-op diet is very important for your safety, not only during surgery, but after as well. A fatty liver is more difficult to retract and more likely to lacerate (or tear), which can cause excessive bleeding and more post-operative pain.

    The liver processes fats and alcohol. The liver must be retracted during surgery (lifted up and moved out of the way of the stomach), which can be difficult in laparoscopic procedures if it is thick or fatty, as this makes it larger, heavier, and more difficult to move.

    As a result of the diet, which greatly restricts carbohydrates prior to surgery, your body will start to use the glycogen stores (or fat) in the liver. This causes the liver to shrink and become more supple, and therefore, easier to move out of the way during surgery.

    In extremely RARE cases, if the surgeon starts the surgery and the liver is found to be too large or heavy, the surgeon may decide, for your safety, not to proceed.


    You will need to discontinue any medications such as Aspirin, Ibuprofen, Plavix, Motrin, NSAIDs, CelebreX, Mobic or certain vitamins/minerals/supplements such as Flax Seed Oil, Vitamin E, Fish Oil or St John's Wart.

    Many are blood thinners and need to be stopped at least 7 days prior to surgery. These types of medications thin the blood and increase the risks during surgery.

    This is in addition to any other specific instructions given by the surgeon, after review of your medical history.

    You will be given a blood thinner by the surgeons while at the hospital.

    The Pre-Op Diet in a Nutshell

    ***You will need to eat LESS than 50 grams of TOTAL carbohydrates and eat at least 60-120 grams of protein daily***

    ***(This ONE sentence IS the entire pre-op diet!)***

    If you are experienced with calculating NET carbohydrates, then you may use the rule of LESS than 40 grams of NET carbs daily. You are to limit your carbohydrate intake, while eating more protein based foods instead. (If you are experienced with the Atkins Diet or a Keto Diet you do not need to read further, just keep the carbs low. If you are not familiar with those two diet protcols and need more instruction please read onward.)

    It is best if you eat REAL (solid) foods and do not do liquid protein shakes only for the pre-op diet. Liquids will come after surgery and we don't want you to get "liquid fatigue", making you more likely to want to cheat later on the post-op diet. 

    Tips for Success

    • Track your food intake: Use an app on your phone, like MyFitnessPal or Chronometer. Count ALL carbohydrates for the actual amount you eat/drink. Watch the serving size and adjust accordingly. Don't forget to log any drinks you consume, that are not zero calories.
    • Stay well hydrated:  Drink non-caloric, non-carbonated fluids and try to drink 64 ounces daily. (Water, GatoradeZero, Crystal Light, etc).
    • You are not limited on quantity or calories: You are only limited on foods that contain carbohydrates. If you're hungry, eat a high protein, low carb snack. (Hard boiled egg, cheese sticks, almonds, piece of meat).
    • Eat enough to be satisfied: You should not be hungry on your pre-op diet. Just remember you are limiting your intake to any meat, fish, cheese, any green vegetables, and staying away from anything made with flour, all grains and all starchy veggies (NO potatoes, corn or carrots).
    • Eat enough Fiber: If you find that you are a bit constipated, you may add some ground flax seed, hemp hearts, or chia seeds to your food (for fiber).
    • Watch out for "XXX-Free" Foods: Please be aware that "gluten-free" does NOT mean low carb. Also, watch out for highly processed Keto/low-carb products, such as the "new" Keto breads. Choose whole foods instead.


    Allowable Food Suggestions

    You're not limited to just these items, they are mainly a starting point to give you some ideas.

    Vegetable Rule: If it grows under the soil, it is probably higher in carbs and if it grows above the soil, it's probably lower in carbs. One exception is corn, which is actually a grain and high in carbohydrates.



    Beef (whole or ground cuts)

    Chicken (whole or ground cuts)

    Turkey (whole or gound cuts)

    Pork (whole or ground cuts)

    Lamb (whole or ground cuts)

    Bison (whole or ground cuts)

    Any Fish,Shellfish,Seafood (fresh, frozen or canned)

    Deli Lunch Meat: Canadian Bacon, Pepperoni, Ham, etc. (make sure any lunch/deli meat does not contain added sugars)

    Eggs (prepared all ways)

    Cheese (most varieties, see below for limited choices)

    All green vegetables PLUS: cauliflower, all color bell peppers, mushrooms, spaghetti squash, and onions



    Condiments: dill pickles, relish, olives, mustard, mayo (not Miracle Whip), hot sauces (Tabasco, salsa), soy sauce, sugar-free salad dressings, lemon/lime, extracts, most vinegars (watch carb count in balsamic)

    Most pure spices and seasonings (watch for spice blends or rubs that contain added sugar)

    Oils (Olive Oil, Avocado Oil, Coconut Oil)

    Real butter (not margarine) or Ghee




    Cottage Cheese


    Yogurt (plain or Two Good brand flavored yogurts, available at Wal-Mart or Dannon Fit-n-Lite)

    **Watch for any added sugars in your dairy products. Count the carbs.

    Peanuts (or peanut butter)

    All other nuts (almonds, macadamia, cashews, hazelnuts, brazil, pistachio, etc.)

    All other nut butters


    Low-glycemic fruits: Examples: rhubarb, berries (raspberries, blackberries, blueberries, strawberries), watermelon, apples (not red delicious variety, more like Fuji apples).

    Condiments and sauces: watch for any added sugars.

    Reduced sugar/ No sugar Ketchup – Heinz has a good one. Avoid the Walden Farm brand at all cost – it is BAD!


    Extremely Limited:

    All beans (legumes): Lentils, split peas



    Avoid ALL:



    Oats (and oatmeal)



    Eliminate all grains from your diet


    Cream of Wheat






    Potatoes (or anything made with potatoes – no french fries, hasbrowns, etc)

    Corn (or anything made with corn)


    No other starchy veggies (when in doubt, Google is your friend)

    Chips (any kind)


    Anything made with flour

    Bad Oils (Safflower Oil, Vegetable Oil, Canola Oil, Margarine or any other processed fats). No deep fried foods.