Bowl of mashed potato, a bariatric liquid diet food for patients who went through weight loss surgery, is on a wooden table

Easy Nutrient-Filled Options for the Bariatric Liquid Diet

Congratulations! Deciding to pursue bariatric surgery is always a challenging choice to make. Even after you’ve decided to go through with it, your head is still swimming with questions and worries. “Why is one of my prescriptions a diet? What is a bariatric liquid diet? How am I supposed to adjust to new foods when my body is still healing?” 

You’re not alone. Worries like this are common when undergoing bariatric surgery, and they all have answers. The bariatric clear liquid diet – and all parts of the bariatric liquid diet – are designed to help your body heal as quickly as possible and avoid complications. 

Adjusting to new foods can feel intimidating, but don’t worry! Many of the foods on this bariatric liquid diet plan are things you’ve tried before (and will have the chance to try again before your surgery). 

Each stage of the bariatric diet is easy to follow once you get the hang of it! 

And remember, your surgery team will be doing their best to take care of you. If anything feels wrong – from unusual pain to uncertainty about a specific food in the bariatric liquid diet – speak up right away so they can get you the help you need. 

But before we start talking about the bariatric liquid diet, let’s take a moment to talk about bariatric surgery itself.

What is bariatric surgery?

Many people who are exploring the possibility of bariatric surgery, or “weight loss surgery” as it’s more commonly known, don’t know much about what it is or why it helps with weight loss. 

There are three kinds of bariatric surgery – Gastric Bypass, Gastric Banding, and Sleeve Gastrectomy. Each has a slightly different approach, and any could be the right fit in different situations. The one thing they all have in common is reducing your stomach’s capacity. 

When someone overeats frequently, the stomach’s capacity grows beyond what the body needs. This means that eating the number of calories your body needs may still leave you feeling hungry. 

Bariatric surgery seeks to solve this problem by reducing your stomach’s capacity so you can feel full on fewer calories again. It’s a simple concept - with a slightly complicated diet plan.

So let’s jump into preparing your body for this surgery and the steps you can take to speed up your recovery!

What is the liquid diet for bariatric surgery?

The “liquid diet for bariatric surgery” can refer to a few different things. There are multiple points throughout preparation and recovery where you’ll be on a liquid diet. Remember, this is surgery on your stomach – the organ responsible for breaking down food so the rest of your body can use it. 

You wouldn’t have surgery on your leg and then expect to run a marathon or even go for a long walk! In the same way, don’t expect your stomach to have surgery and then be able to process a full meal. 

The liquid diet for bariatric surgery is designed to re-introduce solid foods slowly, so your stomach can adjust to its new size. 

There are two kinds of bariatric liquid diets you’ll be following during this process: a clear liquid diet and a full liquid diet. 

What’s the difference between a clear liquid diet and a full liquid diet?

A bariatric clear liquid diet means you can only consume liquids that you can see through. These are liquids that are easiest for your body to process. This kind of diet is used right before and right after surgery when your stomach is at its most vulnerable. 

The full liquid diet is the next phase. During this phase, you’ll start to introduce foods that have a little more heft to them. Your body can still process these easily since there are no chunks of food to break down. They still need to be liquid, but this isn’t as rigid as the clear bariatric liquid diet.

The pre-surgery bariatric liquid diet

Before your surgery, you’ll go on a full liquid diet to prepare your body in several important ways. First and foremost, a pre-bariatric surgery diet will kickstart the weight loss process. Removing the bulk of calories you eat in a day prompts your body to start burning fat, a process that will continue throughout your recovery. 

Secondly, the pre-surgery bariatric liquid diet will shrink your liver. Why does that matter? Well, your liver sits on top of your stomach, so shrinking it will make the surgery go much smoother. A smoother surgery means fewer complications afterward, which leads to a quicker recovery time!

The post-surgery liquid diet

After surgery, your stomach is extremely delicate. The post-surgery clear liquid diet prevents complications by allowing your body time to heal before returning to business as usual. This usually lasts 1 to 7 days and should be over by the time you leave the hospital. 

At that point, you’ll move back to a high-protein bariatric liquid diet for 7 to 14 days. During this time, you’ll incorporate lots of protein, usually in the form of bariatric surgery protein shakes. As long as your body is healing normally, you’ll then move on to soft – but still solid! –  foods. 

Now that you have an idea of what the different stages of the bariatric liquid diet are, let’s take a look at what you can eat during each of them. 

What should you eat on the pre-surgery bariatric diet?

Your surgery team may recommend making changes to your diet as soon as you start planning your surgery – even if it’s months away. You won’t be jumping right to the bariatric liquid diet, though! 

In fact, you’ll more or less be eating as normal, but you’ll remove some foods and add in more of others. 

Foods that are highly processed or contain lots of fat, sodium, or sugar should be replaced with lean proteins, whole grains, and fresh, whole fruits and vegetables. Some examples include: 


  • Chicken
  • Fish
  • Turkey
  • Lean red meat


  • Barley
  • Brown rice
  • Oatmeal
  • Whole wheat


  • Broccoli
  • Carrots
  • Green beans
  • Squash


  • Pomegranate
  • Cranberries
  • Peaches
  • Strawberries

Two weeks before your surgery, you’ll switch to a full liquid diet that’s high in protein and vitamins. This is to give your body everything it needs to make a full, quick recovery – even while you’re not eating solid foods.

Protein is the most central structure of the body, and no kind of protein is more abundant than collagen. Collagen has even been shown to strengthen the tissue that lines the stomach. Best of all, collagen is usually found in liquid or powder form. 

Protein powder for bariatric patients is easy to incorporate into your diet, even when you’re on a full liquid diet. Liquid bariatric vitamins are helpful for the same reason. Your body needs vitamins to build and repair itself, so you’ll need to give your body plenty of them to recover after surgery. Many people undergoing bariatric surgery also have at least one vitamin deficiency. 

After the surgery, it takes time for your body to re-learn how to absorb all the different kinds of vitamins you need to stay healthy. To prevent dangerously low levels of a vitamin, you’ll need to supplement both before and after surgery.

What should you eat on the bariatric clear liquid diet?

Usually, you’ll only be on the clear liquid diet while you’re in the hospital. Foods you eat on the clear liquid diet are very light and easy for your body to process. 

Think back to the last time you had a bad stomach bug. You probably didn’t want to eat a steak dinner! Your stomach will be even more sensitive immediately following surgery, so it’s important not to overdo it. 

Typically, on a clear liquid diet, you’ll only eat: 

  • Water and ice
  • Broth
  • Sugar-free jello and popsicles 
  • Sugar-free, caffeine-free, non-carbonated beverages (such as herbal tea, Crystal Light, or unsweetened juice)

During this phase of the bariatric liquid diet, you’ll be working hard to stay hydrated. This usually means taking tiny, tiny sips of liquids – often with the goal of one ounce every 15 minutes. 

Be patient with yourself and your body during this early healing phase. Tiny sips can be tedious, but don’t give up!  

What should you eat on the bariatric full liquid diet?

You’ll be on the bariatric liquid diet both before and after your surgery. The full liquid diet allows you to give your body more nourishment and variety than the clear liquid diet. Like the clear liquid diet, though, the full liquid diet is easy for your body to process and gentle on your still-healing stomach.

The most important thing to remember about the full liquid diet is that everything should still be liquid. It’s easy to make the mistake of introducing something too solid too soon. After surgery, this can cause severe complications, so double-check everything you eat against these three rules.

First, are there any chunks in the food? Even fruit in yogurt or soft vegetables in soup are too solid for your stomach to process right now and will need to be pureed. 

Second, does the food easily, smoothly pour off of a spoon? If there are any lumps or if you have to wait for gravity to pull the food into your bowl, it’s too thick. 

Third, if you drag a butter knife through the food, does the trail it leaves stay behind or disappear as soon as you remove the knife? If there’s still an indent from your butter knife, the food is too thick. 

Some foods to eat on the bariatric liquid diet at this point include: 

  • Hot cereals (such as Cream of Wheat or Malt-O-Meal)
  • Creamed soups
  • Sugar-free pudding
  • Sugar-free yogurt
  • Instant mashed potatoes
  • Unsweetened applesauce (thinned with water if necessary)
  • Pureed fruit, veggies, or meats

Some of these foods may need to be further thinned with water or milk, and you’ll want to set protein goals with your surgery team. Adding protein powder to any of these meals can make them great alternatives to protein shakes after bariatric surgery.

Preparing for and recovering from bariatric surgery 

Bariatric surgery is a huge choice to make, and the intense preparation and recovery can be nerve-wracking. Let’s go through a quick review of what to expect your meals to look like throughout this process. 

Before your surgery, make sure you’re following the preparation plan your surgery team lays out for you. This usually means eating smaller, healthy meals until the last couple of weeks before your surgery date.

In those couple of weeks, you’ll use the bariatric liquid diet to prepare your body with lots of protein and the best bariatric vitamins. Stay hydrated, and don’t let your nerves get the better of you!

After your surgery, you’ll spend a few days on a clear bariatric liquid diet. You’ll only sip caffeine-free, sugar-free liquids that are watery enough to see through. During this time, your stomach will be healing, so take it slow. 

Then, you’ll spend a few weeks on the full bariatric liquid diet again. It’s critical to meet your vitamin and protein goals during this time. Use protein powder or liquid protein shots to help you meet those goals while keeping a versatile diet.

Most importantly of all, give yourself and your body plenty of time and patience. Healing from a surgery is difficult under any circumstances, and nourishing your body is the best way to speed the process along.