Liver Shrinking Diet

Should You Follow the Liver Shrinking Diet before Surgery?

August 2, 2023

Stress alert! You’ve made an immense decision and decided to have bariatric surgery. Then, you’re informed that it’s not quite as straightforward as you thought. First, you need to follow the liver shrinking diet, also known as the liver reduction diet. Why? What’s this all about? Let’s lower your stress level right now. Here’s what you need to know.

Did you know that one third of you considering bariatric surgery may find out that you have a fatty liver? What does this mean exactly? It’s called non-alcoholic fatty liver disease, abbreviated as NAFLD. This type of fatty liver is different from alcohol induced liver issues. An enlarged liver is tied to extra fat deposited in it and also around it in the abdomen. This is referred to as fatty liver. This large fatty liver increases the potential for complications for you during surgery. Also, this additional abdominal fat can make it difficult for the surgeon to access the liver easily and may complicate the procedure. A smaller size liver makes the surgery easier for everyone.

How is a fatty liver tied to the liver shrinking diet?

This diet helps the body use up stored carbohydrates called glycogen, which is stored in the liver. Reducing the glycogen in your liver helps it to shrink in size, making it easier for the surgeon to move the liver and access the stomach. This specific liver shrinking diet is prescribed as a way to manage non- alcoholic fatty liver disease (NAFLD).

The big short-term benefits to you include weight loss, a smaller size liver, easier access to the stomach during the procedure and less chance for problems after surgery.

Short-Term Benefits of Liver Shrinking Diet:

  • smaller liver size
  • weight loss
  • easier access to stomach during surgery
  • less chance for issues after surgery

Let’s look more closely at what it takes to follow this diet. You can do this if needed. Generally, it’s a 2-4 week pre-surgery diet with reduced daily calories. How low? Typically, 800-1000 calories, though some surgical centers do suggest lower, down to 500 or so. I am NOT a huge fan of dropping calories to 500. This reduced-calorie diet plan is low fat and low carb, so the majority of calories come from protein. It seems that bariatric surgical centers vary in their protocol and criteria for the liver shrinking diet. Some centers prescribe a two- week diet while others recommend four weeks.

Protocol may include only liquids such as protein meal replacement shakes made with high quality complete protein. Protein is key, but don’t miss the words “high quality complete protein”. As a reminder, complete protein contains all of the essential amino acids needed by the body. Essential means that your body does not make these amino acids, so they must come from your food selections. The highest quality complete protein is found in animal sources such as egg, lean meats, dairy or soy. Protein quality is important as protein in this liver shrinking diet helps preserve your lean muscle during weight loss.

At the start of this diet, bariatric vitamin and mineral supplements will likely be suggested if you are not taking them already.

Another choice besides a liquid only diet is a hybrid approach or a mixture of meal replacement shakes plus some food. And other surgical centers may opt for a third option or a liver shrinking diet of real food with very restricted calories (remember 800-1000 calories per day or less). These are the likely options you hear about. My personal favorite is the real food option with the inclusion of low starch/low carbohydrate vegetables including asparagus, broccoli, greens and many other choices.

Consumption of liquids

Your consumption of liquids will also be really important. How much? Two liters or 64-67 ounces per day at least. As you now know, this liver shrinking diet is very restrictive, so it’s smart for you to be under the care of your healthcare team, particularly a bariatric dietitian while you follow it.

If you are prescribed the liver shrinking diet, remember to think about these three things before you begin:

What type of liver shrinking diet are you to follow? It will likely be one of these three: liquids only, a hybrid of liquids and food, or low-calorie foods only. What is the length of time before surgery you need to follow this plan? Do they provide you with a meal plan and communication with a registered dietitian nutritionist (RDN)?

Be sure and make your health care team aware if you have high blood pressure or diabetes and take medications. You want a plan in place to keep your blood glucose and blood pressure stable and to have both monitored. Don’t forget to check your blood glucose and blood pressure more frequently yourself while you follow this diet.

Constipation could be an issue

Constipation could be an issue with this low-calorie diet, so discuss this up front before it might happen. There is no need for you to follow a special diet and get constipated as a result. You don’t want or need that issue to deal with. When it comes to medications for constipation, there may be specific suggestions for what you can take now with surgery in the near future.

Yes, this is a very targeted and specific diet and you may feel like it’s one more thing on your pre-surgery list. Think of it this way. If the liver shrinking diet is prescribed for you, it’s one and done. Short-term and over. Even more important is that following this diet will help you to experience a better surgical outcome and long-term journey.

Registered dietitian nutritionist Dr. Susan Mitchell is host of the podcast Bariatric Surgery Success.

Liver Shrinking Diet
Susan Mitchell


Bariatric dietitian Dr. Susan Mitchell is host of the podcast Bariatric Surgery Success. Selected as one of the Best 35 Dietitian Podcasts, Bariatric Surgery Success was chosen from thousands of podcasts on the web ranked by traffic, social media followers, domain authority & freshness. Dr. Susan helps you conquer cravings, emotional eating and weight regain after bariatric surgery with a focus on your nutrition and health, journey and success. Read more articles by Susan!