Obesity Surgery Center of Monterrey


(also includes medication instruction below)

Gastric By-Pass Pre-Operative Education Guide

Lap-Band Pre-Operative Education Guide

Why is the liquid diet important?

The main reason is that your liver will shrink in size and this will lower the risks during your surgery and after the surgery your post-op will be more pleasant. This can also mean less time in the operating room and less incisions in your abdomen.

What happens if I don't follow the preoperative liquid diet before surgery?

If the diet is not followed as instructed, you will have more risks during surgery, such risks include larger incisions, the possibility of leaving a feeding tube in your belly, having to convert your surgery to open surgery which will increase the costs of your surgery and even the risk of the surgery not being able to be performed.

What happens if I eat some type of solid food while I am doing the liquid diet?

It doesn't really matter, if it is a little bit of solid or a lot, eating solids during the liquid diet will ruin it completely. You will have thrown away all the effort you had made so far.

Are protein shakes allowed?

Yes, protein shakes are a very important part of your liquid diet. Remember the amount of protein must be 60 - 70 grams a day.

How much liquids am I allowed to have during the day?

Drink at least 10 to 12 glasses of liquids every day, (3/4 of a gallon). HYDRATION is very IMPORTANT before surgery to diminish any form of embolism.

Why am I allowed full liquids at the beginning and only clear liquids after?

The last days before surgery we are trying to maximize the effect of being in a low calorie high protein diet. It is important to stay away from fat during this period and try not to go over 50gr of carbs a day.

Is salad allowed?


What happens the night before surgery?

The last day of your liquid diet is the most important, so you can only have clear liquids during the day and by midnight you will not be allowed to have anything else, not even water.

How many days do I have to do?


If your BMI is:

< 351 day (clear liquids)
35-453 days (clear liquids)
46-557 days (3 days of full liquids & 4 days of clear liquids)
> 5510 days (5 days of full liquids & 5 days of clear liquids)


If your BMI is:

35-455 days (clear liquids)
>4510 days (3 days of full liquids & 7 days of clear liquids)

Clear liquids:

  • Chicken, beef or fish broth
  • Crystal Light
  • Tea
  • Free sugar Gelatin
  • Sugar free Popsicles
  • Fruit juices (25% juice, 75% water)
  • Lemonade with splenda

Full liquids:

  • Anything on the above list
  • Skim milk
  • Yogurt light
  • Cream of wheat, Malt o meal, Cream of Rice (add extra liquid)
  • Oat meal (pureed)
  • Fruit shakes (with water or milk and splenda)
  • Low fat soups (chicken, beef or vegetables blended)
  • Sugar free smoothies

Protein Shakes:

*Optimum Nutrition23g5g1.5g
Advantage Edge15g3g3g
Perfect Start Plus20g8g2g

Blend Protein shakes with WATER and some ice.

*Optimum Nutrition tastes the best. You can buy this at allstarhealth.com or 'The Vitamin Shoppe'.

Stay away from fat during this period. Try not to go over 50gr of carbs a day and the amount of protein must be 60 - 70 grams a day.

You have to drink two to three quarts of liquids a day.


  • Carbonated beverages
  • Concentrated sweets (fruit juice, ice cream, chocolate milk or flavored milk products)
  • Alcohol
  • Smoking - It is important that you quit smoking two weeks before your surgery and one month after. Smoking can lead to complications that can be easily avoided if you will simply follow these guidelines.

Remember that these examples are just a guideline, the most important thing to pay attention to is the texture of your food. It should be comparable to the consistency of the foods above.


The following is a list of surgery requirements for those having surgery with either a Local or General Anesthetic:
DO NOT take any of the following products 10 days prior to surgery:

Aspirin/Baby Aspirin, Alka Seltzer, Anaprox/Naproxen, Plavix, Coated Aspirin/ASA, Feldene, Coumadin, Anacin/Excedrin, Ibuprofen/Motrin/Advil, Warfarin, Fiorinal, Voltara/Diclofenac, Robaxisal, Toradol, Midol, Alleve (USA), Indocid, All Herbals, Vitamin Supplements & Multivitamins, Sunflower seeds, Cod-liver Oil/Fish oil capsules, Green Tea, Garlic Pills, Ginger, Vitamin E, Sushi, Omega -3,-6 fatty acids, Salmon, Tuna - As these are known Blood thinners. Ask your physician for instructions on medications for diabetes or other blood thinners.

Please take any pills that you normally take the day of surgery, with a small sip of water, unless you are told not to. If you are a diabetic, please bring your glucometer with you. Also make sure to bring your pill crusher/cutter if you are on medications, it can be any brand.

If you have ANY questions about stopping any of these medications, contact us at cathy@gastricband.com and we will put you in touch with a doctor or ask your primary physician.

These are the instructions of the physicians at the Obesity Surgery Center of Monterrey.

To download this file click here.

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Punto Central Building
Avenida de la Industria No. 300
C Tower, First Floor, No. 8
Fracc. Desarrollo Punto Central
San Pedro Garza Garcia, C.P. 66279
Tel: (52-81) 8347-4481 or
(52-81) 8333-6891
Fax: (52-81) 8347-4481