Pre Bariatric Surgery Diet 

One of the questions that we are often asked when somebody is considering bariatric surgery is whether or not they need to lose weight before they are able to have surgery. In many cases, the reason that the patient is considering surgery is because they are finding it difficult to lose weight on their own, so having to lose weight to be able to have the surgery can be a daunting prospect.  

Do you need to lose weight before bariatric surgery?  

There isn’t a set answer for every patient, as each patient is different, but in short the answer is yes. Pre-bariatric surgery patients are put on a very low calorie diet (VLCD) in advance of their surgery in order to reduce the size of the liver as much as possible. Reducing the size of the liver pre-surgery can mean that there is ‘more room’ to operate and essentially make the surgery safer for the patient.   

How much weight do I need to lose before bariatric surgery?  

As above there isn’t a set answer for every patient. Depending on the patient’s original BMI will determine how much weight they need to lose before surgery, or how long they need to be on a VLCD for. The focus of the pre-surgery diet is to reduce liver size, not your weight.  

How do I lose weight before bariatric surgery?  

At Upper GI Surgery we ask our patients to follow a VLCD prior to surgery using Optifast® meal replacements, such as shakes/soups/bars. So let’s look at how the VLCD Optifast® works:  

• Low carbohydrate, total food replacement.  
• Provides 800 calories or less per day.  
• Consists of sufficient protein, fatty acids, carbohydrates, vitamins and minerals for safe and rapid weight loss.  

• Leads to a whole body shift towards fat stores being utilised as the major source of energy through mild ketosis.  

Our dietitian will assess your original weight and BMI and decide how long you need to follow the VLCD for prior to your surgery. For some people this may be 2 weeks, but for others it could be 4 – 6 weeks.  

Preparing you for the future 

Even though the VLCD is used to reduce liver size pre surgery, it is actually a good ‘test’ to see how you will cope with the dietary changes following surgery. Once a patient has had bariatric surgery they are unable to eat solid food for some time and therefore are required to only consume liquidised food (thinly blended food i.e. smoothies or soups) or meal replacement shakes. By using meal replacement shakes at this time you can greatly assist the daily nourishment and protein requirements.  

Although sticking to the VLCD prior to bariatric surgery may be difficult for patients, often they find that following surgery it is much easier to adhere to this style of diet due hunger reduction as a result of the surgery. 

If you would like to discuss your options with us or would like any more information please call our clinic on 02 9553 1120 to make an appointment or contact us online.