The Full Liquid Diet for Bariatric Gastric Band Post-Surgery Patients

What to Eat and Drink During Post- Op Gastric Bypass Bariatric Surgery

When recovering from gastric bypass surgery it is more important than ever to ensure you are following the guidelines of your medical professional as they create a plan and set specific guidelines for you dependent on many factors including your medical history. However, the one rule all medical professionals have that applies to all patients is following a liquid only diet in the first and second week of your gastric bypass post-operation. Below are some key recommendations by medical professionals and nutritionists alike and a step by step guide on how to correctly prepare post-operation. 

For the first five days following bariatric surgery, you will need to follow an entirely fully liquid diet. This includes clear liquids and full liquids. At this stage of the process, since your body is still in the beginning stages of recovery, it is important to follow this guideline to a "T" to avoid potential health implications. Avoid drinking your liquids through a straw as often as possible, as drinking through a straw puts unnecessary strain onto the stomach as it adds gas, and your body is already full of excess air. 

How Do I Ensure I Am Getting Enough Nutrition if I Can Only Drink Liquids?

A great way to ensure you are getting enough nutrition is to ensure you are drinking at least 1.5 liters of any of the nutritious liquids mentioned below to ensure you are not only getting the nutrition you need, but you are also staying hydrated throughout the day. To avoid feeling full too soon and on-set discomfort, do not gulp down your liquids in one setting, instead take small sips every few minutes. Doing this will help ease any on-set discomfort such as stomach pain. Over time, your body will react to the liquids, and you will be able to drink more as your body adjusts after post-op gastric surgery. 

Best Liquids to Drink Post-Op Surgery

As mentioned above, it is important that you drink only clear or full liquids for the first five days that also provide nutrition.The best options are full liquids that are packed with nutrition, which includes protein shakes- however all protein shakes are not created equal- keep in mind they cannot contain sugar, and the protein content needs to be at least fifteen grams per serving.  

  • Sugar Free Protein Shakes –We recommend Protein Milkshake as it contains 22 grams of protein, is sugar-free, and has a whey and vegan option.
  • Skimmed or semi-skimmed milk fortified with skimmed milk powder (1-2 tablespoons per 200ml).
  • Soups made from chicken stock, light consomme, bouillion or plain water (1 cup per serving).
  • Unsweetened diluted fruit juices. Dilute the unsweetened fruit juice 1:3 with water to lower the calorie content. Ensure not to drink more than one glass a day. 
  • Black Coffee or Unsweetened Tea of choice (no milk or sugar- only exception is skimmed milk). 

Liquids to Avoid Drinking Post-Op Surgery

Now that you know the liquids approved for after post-op surgery, it is important for you to know the drinks to avoid.

It is important to ensure you refrain from some drinks as not all beverages are created equal when it comes to your health. 

To avoid gas buildup, stay away from carbonated drinks such as cola as they can have negative effects when consumed after gastric bypass surgery, including severe pain to your stomach. 

  • Wait at least 30 minutes after each meal. Then consume eight ounces of Protein Milkshake followed by 16 ounces of sugar free, clear liquids.

  • Try to spread fluids out over a three-hour period.

  • Stop drinking at least 30 minutes before mealtime.

Note: Remember, your stomach is still recovering from post-operational surgery. It's common to experience nausea or vomiting at this point. Please keep yourself hydrated with clear or full liquids

Example Recommended Full Liquid Diet for Post-Op Surgery Meal Plan One



  • ½ cup fat free yogurt (no added sugar)


  • ½ cup strained, low fat cream soup

Ensure you are drinking clear liquids between meals- around thirty minutes after each meal. 

Example Recommended Full Liquid Diet for Gastric Post-Op Surgery Meal Plan Two

  • Unsweetened and distilled fruit juice (200ml)
  • Thin soup of choice in chicken broth

Recap: Important Things To Remember After Surgery

During the full liquid diet phase following your lap band surgery:

  • Consume six to eight 8-ounce cups per day. 
  • Consume ½ cup of full liquid fluids at each meal.
  • Start drinking clear liquids 30 minutes after each meal.
  • In most cases you want to consume at least five bariatric full liquids a day which include water, coffee or tea with no added sugar or milk, Protein Milkshake, and clear soup.

Remember that you need to maintain a healthy bariatric diet to have a successful post-op surgery, however you are not in this alone. If you are looking for guidance on how to make bariatric protein shakes and smoothies- or need daily dose of motivation, check out our full set of bariatric-friendly smoothie and protein shake recipes here and follow us @proteinmilkshake on IG for motivation and support during your post-op journey. 


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