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Bariatric Surgery Diet: What You'll Eat Before Surgery

By Meagan Drillinger
For patients who are scheduled to undergo bariatric surgery, your surgeon may require you to try a special diet prior to the procedure.

For patients who are scheduled to undergo bariatric surgery, your surgeon may require you to try a special diet prior to the procedure.

Bariatric surgeries are weight-loss procedures that involve making changes to the digestive system. It’s a solution for patients with a body mass index (BMI) of 40 or higher who have been unable to achieve a healthy weight-loss for a period of time.

What will you eat before bariatric surgery?

If you qualify for bariatric surgery, your team of professionals, including a surgeon and dietician, will recommend a diet, which may include restricting certain foods and medications. The diet may also include protein supplements, usually protein powders or shakes, decreasing all fats, decreasing sugary foods and drinks, and decreasing high-carbohydrate foods, like white bread and white pasta.

Many bariatric surgery centers put patients on an all-liquid diet as a way to promote rapid weight loss. However, other centers focus on long-term weight-loss and changing behavior to promote healthy eating habits.

“Most bariatric programs require working with a dietician for several months before surgery,” says Sharon Zarabi, RD, CDN, CPT, Bariatric Program Director, Lenox Hill Hospital, New York City. “Myself and my colleagues work on creating new eating habits and improving eating behavior, including incorporating more plant-based foods, more fiber, protein, healthy fats, and limiting carbohydrates.”

How far in advance should patients begin this diet?

According to Zarabi, most centers start an intense diet about two weeks before surgery. Other centers that focus more on lifestyle choices begin recommending eating behavior modification right away.

What is the purpose of a pre-surgery diet?

There are several reasons why your surgeon might recommend a pre-surgery diet, but one of the most common reasons is to shrink the liver.

“When most patients have an elevated BMI, they also have fatty liver disease,” says Zarabi. “This is when excess fat cells accumulate on the liver, which is located approximate to the stomach. Surgeons ask patients to lose some weight before surgery to shrink the liver, which decreases operating time and risk for injury.”

Other reasons for following a pre-surgery diet include:

  • Preserving and protecting muscle tissue
  • Preparing the body for surgery and recovery
  • Preparing the patient for a post-surgery diet

Other pre-surgery requirements

Your surgeon may also request the following prior to bariatric surgery:

  • Avoid alcohol
  • Stop smoking
  • Avoid binge-eating
  • Stop certain over-the-counter medications and prescription medications. Ask your doctor to specify what is right for you.