Bariatric Diet - What You Can And Can't Eat

Updated: Sep 23, 2019


• Ensure you eat high-protein & low-carb

• Do NOT eat 'one last big, unhealthy meal' before surgery

After you have weight loss surgery, you will need to make some significant changes to your diet in order to maximise the amount of weight you’ll lose.

The right bariatric diet and eating techniques include:

  • Eating a high-protein, low-carb diet, & no cheating before surgery

  • A slow transition from clear liquids to solid foods after your surgery

  • Eating whole, healthy foods each meal with your proteins being eaten first

  • Drinking a Lot of sugar-free liquids, but never around meals

  • Minimal snacking throughout your day

  • Serving small portion sizes, and making sure you chew every bite thoroughly

  • Following your prescribed post-surgery vitamin regimen

  • Avoiding “trigger” foods and alcohol

How you should eat after weight loss surgery

Getting into the right diet plan before surgery and sticking to it is important for 3 reasons…

  1. The higher your body mass index before surgery, the more likely you are to develop complications. Getting your diet in line well before surgery will bring down your BMI and reduce your risks.

  2. It gives your body the energy and nutrients it needs to heal from surgery and function properly during extreme weight loss.

  3. It helps to avoid bariatric surgery complications down the road while maximising weight loss and maintenance.

Conventional wisdom may tell you, “You’re getting bariatric surgery soon, so now’s the time to live it up!” But you must have the complete opposite mentality.

From the moment you begin to seriously consider weight loss surgery, your diet habits should change forever. Consider the months leading up to surgery as a test.

You are training yourself to have discipline with food and learning the motivation it will take to reach your goals. The right bariatric surgeon will help.

Part of the process of choosing a good doctor is learning about the dietitian or nutritionist that they partner with or have on staff.

The dietitian will talk with you about your diet history and will help you understand what kind of eater you are. In addition to pointing you towards the bariatric treatment that will would be best to your habits, they will set you on an appropriate prebariatric surgery diet.

Their involvement is also important from a financial perspective. Many bariatric insurance providers require that you go through a medically-supervised weight loss program before they approve your surgery.

“…NO one last big unhealthy meal before surgery.”

Your pre-surgery bariatric diet

Your pre-surgery bariatric diet will most likely be high-protein and low-carbohydrate with plenty of fluids (do not take appetite suppressants).

For the two weeks leading up to surgery, you’re bariatric diet will most likely be a liquid one and your daily calories will be at or below 1,000.

To ensure you’re getting the right nutrients, your dietitian may also prescribe bariatric vitamins.

A high-protein/low-carbohydrate bariatric diet is important for 3 big reasons…

1. Reduces bleeding

2. Promotes healing

3. Shrinks your liver – an enlarged liver can make surgery more difficult by blocking the surgeon’s view and increase the risk of your liver being damaged during surgery.

We’re sorry to say that this means no “one last big unhealthy meal” before surgery.

You will slowly transition from clear liquids to solid foods.

As per your post Surgical instructions - Your surgeon-recommended Diet or nutritionist will also have you on a detailed bariatric surgery diet plan for the first several weeks after surgery.

Following their advice exactly will promote healing and start you on your permanent (and more enjoyable) bariatric diet while minimising negative side-effects…

  • You’ll only be able to have liquids for the first couple of days following surgery. Hospital meals will probably include broth, water and possibly juice, although you may find that juice upsets your stomach at first.

  • Your liquid bariatric diet may only be an ounce at first. Yes, an ounce! That’s about the equivalent of two tablespoons.

Blend It!

Starting around week 2, your blender will become an integral part of your meal preparation. Even after you’re completely healed, smoothies and pureed meals will compliment your bariatric diet well and are a great place to include your extra protein if necessary. If you don’t have a great blender already, we strongly recommend investing in one.

  • Adding powdered protein to your bariatric diet will follow your liquid-only diet for a week or two, but the mixture should still be water-like. Certain soups will probably be okay as long as they don’t have any solids in them. During the first week, your doctor will most likely recommend that you sip a few ounces of your liquid meals every hour or so.

  • From the 2nd through the 6th weeks, your liquid meals will get thicker and thicker (but still completely pureed with no small bits remaining). Solid foods will be out of the question. Eating 4 to 5 three ounce meals a day is normal. Your tiny stomach won’t be able to hold much, so expect to feel full very quickly. Foods appropriate for this stage include cream soups and yogurt-based smoothies.

  • As soon as possible, your doctor will have you eating solid foods which will make you feel full sooner. This could happen as soon as the fourth week, although the average patient gets there between 6 and 8 weeks. At that point, your bariatric diet will consist of 3 four-ounce “normal” meals per day.

  • Introduce foods back slowly to figure out which foods your system can and can’t tolerate. Anything too fibrous, such as raw vegetables, may be too much for your system to handle at first. You’ll need to cook everything well and chew it thoroughly before swallowing.

After 6 to 8 weeks or so, you’ll be fully transitioned into your new permanent bariatric diet.

IMPORTANT: For the first few months following surgery you need to be very mindful of avoiding dehydration. Your body will need about 8 cups per day.

Not getting enough can lead to nausea and persistent vomiting which, in turn, can lead to vitamin deficiencies and put you back in the hospital.

#bariatricsurgery #whattoeat #hubtransformed

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A big thank you to the beautiful Alyce for allowing us to share her inspirational story. We are so proud of everything you have achieved Alyce! "My journey started with Your Health Hub in June 2020 a

"When I joined [Transformed], I had been on a waiting list for Bariatric surgery for almost a year and had given up hope on most methods of weight loss.


But after signing up and meeting the team I felt so supported that I was willing to try. In 6 months I lost 40kg and have my life back."

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