Working time: Mon – Fri: 08:00AM – 4:30PM

What you need to know about the diet before gastric sleeve surgery

What you need to know about the diet before gastric sleeve surgery | Brisbane Obesity Clinic

What you need to know about the diet before gastric sleeve surgery

There is one burning question that everyone has on their mind when they meet their dietitian for the first time and it’s always “what’s the diet before gastric sleeve surgery?”. This is always followed by “how long will I need to be on the diet?”.


We answer these FAQs and more below.


What does the pre-surgery diet look like and how does it work?

Patients will need to follow a Very Low-Calorie Diet (VLCD) prior to their surgery. The VLCD diet promotes rapid and weight loss by generating a metabolic shift known as ketosis. This is when the body begins to use its fat reserves as a source of energy. It will reduce the amount of the fat contained in the liver, making it smaller and easier for the surgeon to move.


Why is the pre-bariatric surgery diet important?

It’s all about giving your surgery the best chance of success.

The diet is designed to help reduce the size of the liver, which is often enlarged in overweight patients. Because part of the liver lies across the stomach, reducing its size before surgery means your surgeon will have better access to the stomach, making the procedure safer.


How long do I need to be on the pre-bariatric surgery diet?

The length of time a patient will need to be on a pre-op diet will depend on an assessment by the surgery and dietitian. Typically, this pre-op diet spans two to four weeks.


Am I only allowed shakes?

Contrary to what you might think, the pre-op diet isn’t just shakes. Yes, you’ll consume three high-protein, nutritionally complete medical weight loss shakes daily, but there’s also room for variety.

You’re encouraged to add non-starchy vegetables, salads, and a piece of fruit to your meals. Carbohydrate-rich foods, however, are off-limits.


How strict does the diet have to be?

To the letter. Adherence is mandatory.

Straying from the prescribed plan can jeopardise your surgery, potentially leading to a reschedule. Your dietitian will provide detailed instructions to ensure you have a clear plan to follow.


What can I drink while on the diet?

As for hydration, drinking at least two litres of water or other calorie-free fluids daily is essential. Your dietitian will guide you on what’s best to drink and what to avoid.


What if I am on a special diet for a diagnosed health condition?

If you’re managing a specific health condition that requires a special diet, don’t worry. Your dietitian can prescribe a pre-op diet to meet your unique dietary needs and ensure you stay on track for surgery without compromising your health.


Have more questions about the diet before gastric sleeve surgery?

Remember, the road to surgery is a partnership between you and your medical team, and it all starts with preparation, including following your pre-surgery diet to a tee.

If there’s anything you’re unsure about or if you have questions, we’re here for you. Whether it’s to clear up any confusion about the diet, discuss any concerns, or if you’re ready to take the leap and schedule your consultation, give our office a call.



Brisbane Obesity Surgery | Weight Loss Surgery | Brisbane Obesity Clinic

Are ready to make some decisions about your health?

Working hour

Mon – Fri: 8 a.m. – 4:30 p.m.
Sat – Sun: Closed

Evan Thomson Building, 13/24 Chasely St, Auchenflower QLD 4066

Follow us: