Throughout my career as a bariatric surgeon, I have seen hundreds of patients prior to their bariatric surgery.

I have explained to them all the requirements needed in order to qualify for surgery and by far the one requirement that always makes them hesitant is the 2 weeks Pre Bariatric Surgery Liquid Diet.

What is the Pre Bariatric Surgery Liquid Diet?

The Pre Bariatric Surgery Liquid Diet is nothing else than a Low Carbs, Low Fat, High Protein diet mainly composed of liquids.  It is recommended to keep the calorie count between 600-1200 calories per day.

For more details regarding what to eat during these 2 weeks see my previous blog post link below.

In this blog post, I will focus on the seven reasons why most bariatric surgeons around the world recommend two weeks of “torture” prior to surgery. Hopefully, after you finish reading the post all your questions regarding Why a liquid diet? are answered.

The seven reasons are not placed in any particular order. In my opinion, ALL are important in many different ways.

Reason #1: Weight Loss

On the Pre Bariatric Surgery Liquid Diet, most patients will lose somewhere between 10-15 pounds on average.  Remember, the main reason why you are undergoing bariatric surgery is to lose weight.

The Low Carbs, Low Fat, High Protein, Low-Calorie nature of this diet will start that process for you.  The more weight you lose prior to surgery the better.

Weight loss surgery in thinner patients is always easier and it has lower complication rates. So any weight loss prior to surgery is always welcome. 

The amount of pounds that you will lose depends on your initial weight.  The heavier you are the more weight you should lose.

It is also dependent on your sex. Male patients usually lose more weight than females.  This is particularly true for older females.

Muscle is the calorie-burning machine of the body.  Males, in general, have more muscle mass than females and by default, they have a higher metabolism.

Also, as you get older some of that muscle mass is lost. Older patients need to work harder to lose a significant amount of weight.

If you want to increase your success before or after bariatric surgery, exercise. That will take us to reason #2.

Reason #2: Lean Muscle Preservation

During rapid weight loss, it’s almost impossible not to lose muscle mass.  That is particularly true after bariatric surgery.  

Malabsorption procedures like the Roux en Y Gastric Bypass and Duodenal Switch are notorious for this.

One of the main ways that bariatric surgeons try to minimize the issue is by increasing protein intake on the diet.  

It starts with a liquid diet.

Remember that I said the Pre Bariatric Surgery Liquid Diet is a HIGH PROTEIN DIET.  Most bariatric surgeons will recommend at least 60-80 grams of protein per day.  That number is related to your weight and activity level. 

If you work out a lot, you will need a higher concentration of protein in your diet.  Consult with your doctor and/or dietitian to see how many grams of protein you should be getting on a daily basis.

Patients with kidney and/or liver disease should be careful how much protein they intake as this can be detrimental to their condition.  If you are on dialysis or have liver cirrhosis please consult with your provider before starting the Pre Bariatric Surgery Liquid Diet.

Many patients, especially female patients think that in order to lose weight the need to spend countless hours on a treadmill.  Cardio is definitely important but remember to alternate your workout. Lift weights several times a week to preserve and to gain muscle mass.

Work out the big muscle groups like the hamstrings and the back muscles. Use muscle confusion to your advantage by alternating between cardio and weight training.

If you are morbidly obese you might not need extra weights. Use your own body weight. Squats, push-ups, pull-ups, jumping jacks, lunges, and other exercises can be done using only your own body weight. Start slow and work your way up.

Remember the important thing is to get started.  Excuses don’t burn calories.

Get going. 

Reason #3: Decrease Liver Size

Reason number three is, in my opinion, the most important one.  As you gained weight your liver grew with you. You get was it’s called a Fatty Liver.  

The problem with having a large liver during bariatric surgery is that your surgeon might not be able to complete the operation.

Let me explain.

The stomach is located under the liver. During surgery, your bariatric surgeon will elevate the liver to get to the stomach so he can make it smaller so you can lose weight.

If your liver is excessively enlarged, the surgeon might not be able to get to the stomach.  I saw two patients during my residency at the University of Florida in Gainesville prior to implementing the liquid diet that the surgery had to be aborted due to a large liver.

It is scientifically proven that just 2 weeks on a Low Fat, Low Carbs, High Protein, Low-Calorie diet will decrease your liver size by at least 25 percent.

So, don’t take the chance.  Stick to the diet and your surgery most likely will be completed as planned.

Reason #4: Mental Awareness

After weight loss surgery you will continue the liquid diet.  There will be some changes but for the most part, a liquid diet for 1-2 weeks after surgery is the standard of care.  We want your staple lines and connections to heal well after surgery. You don’t want to eat solid food right away and disrupt one of these connections. That could be detrimental to your outcome. 

Your diet will be advanced slowly in a period of approximately 6 weeks. Please follow the guidelines given to you by your bariatric surgery program.

Doing the liquid diet before surgery will teach you what to eat after the surgery.  Hopefully, you developed mental awareness about portions, calories, and ingredients in your diet.

One good news.

After surgery most likely you will not be hungry, so the liquid diet phase should be a lot easier.

You want to keep the mental awareness or your knowledge during the later stages of your diet after surgery. The new eating habits will help you to lose more weight but also and perhaps more importantly, keeping the weight off.

Approximately 25% of the patients that underwent bariatric surgery will regain some or all the weight back. This is mainly caused by a lack of Mental Awareness, lack of discipline or self-control. Bariatric surgery is only a tool to help you lose weight.

You need to make a commitment to the change.  A lifestyle change.

Reason #5: Adaptation

I briefly mentioned this above but hunger is an issue early on the Pre Bariatric Liquid Diet.  Don’t worry your body will ADAPT.

You will be hungry, especially the first few days during the Pre Bariatric Surgery Liquid Diet.  Your body is very smart and it will stop craving all the junk food that you have been eating.

The main reason why the body craves sweets, sodas, or junk food is because you give it to it.  If you stopped eating that Coca-Cola or Krispy Kreme donuts the cravings will go away after a few days. Think about a cocaine addict, they crave cocaine because they give their body cocaine.  Hopefully, you don’t crave cocaine because you have never given your body cocaine. If you try it you will want to have it again.

We are made to adapt.  Adaptation is one of the main reasons why humans are so successful at so many things.  We adapt, we pivot, we can use our brains in many good ways.  Nutrition is no different.

The diet will be hard at the beginning, every patient will tell me that the first 3-4 days are tough but they all survived.

Trust me, YOU will also survive.

Some of the more active patients will complain mainly of feeling weak.  That is particularly true if you are staying in a very low-calorie range.  If that is the case you might need to increase your calorie intake slowly until you stop feeling the weakness.  Remember that you need to give the body some fuel to perform the functions that you are demanding. Use good fuel, not CARBage.  Focus on protein to fuel your body during the two weeks.

Reason #6: Clean Stomach

I have a story that will explain reason #6 very well.

Back in 2009 when I was a chief resident I did a laparoscopic sleeve gastrectomy with one of my mentors.  We did the case normally and the patient had absolutely no issues but a lot of things could have gone wrong for the patient just because he didn’t follow the diet.

During his surgery, we notice that the patient’s stomach was larger and heavier than normal but we divided the stomach without issues.  At the end of the procedure, we did a routine endoscopy to evaluate the sleeve and to check for leaks.  An endoscopy is basically putting a camera through your mouth down to the stomach so we can see the stomach from the inside.

To our surprise, we found pieces of chicken between the staple lines.

Are you kidding me?  The patient put his own life at risk for a piece of chicken right before surgery.  Again nothing happened to the patient but the learning point here is don’t do it.

It’s not worth it.

Apparently this patient was a sleepwalker and the night before the surgery he went to the fridge and eat some leftover Chinese food with chicken broccoli.

True story…

We need your stomach clean.  Old pieces of food inside the stomach will increase the chances of complications.  It also increases the number of bacteria inside your stomach, again increasing the chance of infection.

Also, it will feel very good to you knowing that you put your best foot forward. Yes, You did it.

The hunger did not win, the hunger did not dictate your outcomes. After all, it brought you to the point of needing weight loss surgery.  Show your body that you are in charge. Tell your body it’s time for a change and you are in full command now.

Reason #7: Save Money

Yes, you will save money.  Who doesn’t like to save money?

Even though you will have to buy the protein drinks of your choice.  I know they cost money, but you will stop eating steak, chicken, and other more expensive solid foods.  At the end of the day, it will save you some dinero.

Use your imagination, shop around. Find sales.

A good number of my patients love the protein drinks from Sam’s Club.  They are called Premier Protein and you can get a 12 pack for under 20 dollars.  They have only 1 gm of sugar and 30 grams of protein.

Amazon has a great variety of protein drinks at good prices.  If you have Amazon Prime you get free shipping.  You can buy premixed shakes or the cheaper powder protein to mix at home.

Pick one that you like an stick to it.  You will use them for several weeks before and after surgery.

So, in conclusion, I will say that the Pre Bariatric Surgery Liquid Diet for two weeks is not the most exciting part of weight loss surgery but is as necessary as the surgery itself.  Every bariatric program has its own rules regarding the liquid diet so check with your program.  In my program, we follow what is outlined in the liquid diet post.  That is post is a guide, you can modify it to your own situation or liking.

Thank you for taking the time to read this post.  Feel free to share it with friends or family. Leave a comment below or if you have a question feel free to ask HERE.

If you live in the North Central Florida area and want an appointment call (352) 291-0239.  I will be happy to discuss your weight loss surgery needs.

Once again thank you so much and I appreciate your time and interest.