The Power of Nutrition: Preparing for Bariatric Surgery

You know you’re ready to take the next step on your weight loss journey, and you know that you want bariatric surgery. But you’re not sure about the pre-surgery diet. What is it, what does it entail, and why is it so important?

In this blog post we’ll review your pre-bariatric diet plan, why it matters, and what it looks like at each step along the way.

What Is the 6-Month Diet Before Bariatric Surgery?

Six months before bariatric surgery, you should start making incremental changes to your diet and exercise habits in consultation with a registered bariatric dietitian. Now is a good time to start eating lean meats (such as poultry and chicken) and fresh fruits and vegetables (raw or steamed). It’s also a good time to reduce your consumption of fatty meats such as bacon and beef ribeye, as well as added sugars and empty calories such as those found in soda and candy.

Why are these dietary changes before surgery so important? First, bariatric surgery is a powerful tool to help you level the playing field in your battle against obesity, but it’s not a magical pill. After surgery, you’ll need to be very diligent about sticking to a healthy diet and exercise regimen in order to give yourself your best opportunity to lose the weight, keep it off, and get your life back. Many of our patients find that it’s easier psychologically to make these changes before surgery, so that by the time they undergo surgery the habits are already ingrained.

According to Lisa Micetich, a dietitian and manager of Food & Nutrition Services at OSF HealthCare Little Company of Mary Medical Center in Evergreen Park, Illinois, “The better you do in this stage, the better your chances of success after surgery.” “As soon as you’ve made the decision to have surgery,” she says, “you should start modifying your behavior.”

The second reason that pre-bariatric-surgery nutrition is so important is that it can help to reduce any risks associated with surgery. A healthy diet (and especially the liquid diet that you’ll adopt 1 week out from surgery) can help shrink your liver and remove some excess body fat. Because the liver sits on top of the stomach, a fatty liver can make it harder to operate on some patients’ stomachs. When the liver shrinks, minimally invasive approaches operations become substantially easier. At a certified ASMBS comprehensive MBSAQIP center like the BMCC, your surgery is already as safe as any minor outpatient surgery. However, it’s very important to our bariatric surgeon to minimize the (already small) risk of complications.

Ultimately, a big part of pre-bariatric-surgery nutrition is improving your physical readiness for surgery and also cultivating healthy eating habits that will put you in good stead after surgery.

How Many Calories Should I Eat On A Pre-Op Surgery Diet?

We don’t always recommend cutting calories at this stage. Getting the behaviors down, and shifting to a healthier diet, is more important than counting calories. That said, if you are motivated to count calories, then our registered dietitian can help you to put together a plan.

What Should I Eat 1 Week Before Bariatric Surgery?

One week before surgery, you will need to adopt a liquid diet. This liquid diet will be low in sugar and low in fat, low in carbs, and high in protein. While every patient’s diet is unique, this phase of your pre-bariatric-surgery diet will probably entail:

– protein drinks (you’ll need to consume 60-80 grams of protein per day)

– low-sodium broth

– water

– sugar-free popsicles

– caffeine-free (herbal) tea

On the liquid diet, you should avoid:

– sugary drinks

– carbonated beverages

– caffeine


This liquid diet will further shrink your liver, making surgery easier and safer. The protein will also help with tissue repair and recovery post-surgery.

Taking the Next Step: Scheduling Your Bariatric Surgery

Bariatric surgery is one of the best gifts that you can give yourself. Sticking to a strict diet pre- and post-op is not easy, but your health and your life are absolutely worth the mental and emotional investment.

If you’re considering bariatric surgery and want to know more about what your pre-op diet will look like, we encourage you to contact our friendly staff or make an appointment.

Our patients routinely say that surgery was the best decision they ever made.

“I feel like I have won the lottery and have been given a second chance in life! March 25, 2014 was the first day of the rest of my new life and I can’t even start to express in words how grateful I am.”—Rochelle Goforth, patient.

If you’re suffering, don’t wait. Contact our Denver office today.

Dr. Joshua Long headshot

This page was medically reviewed by Dr. Joshua Long, MD, MBA, FACS, FASMBS. Dr. Long is a double-board-certified bariatric surgeon and bariatric medical director for Parker Adventist Hospital.
Full Bio: Dr. Joshua Long, MD, MBA, FACS, FASMBS
Page Updated: September 13th, 2023

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