The What, Why and How of the VLED Pre Surgery Diet

VLED Pre Surgery Diet

By Sally-Anne Livock
Bariatric Dietitian

It’s common practice to use a very low energy diet (VLED) in preparation for bariatric surgery.


A VLED is a diet that provides a reduced energy intake (usually around 3350kj) along with a reduced carbohydrate intake (usually ranging 50-100g of carbohydrate daily).

Traditionally, meal replacement shakes have been used as the main source of energy prior to bariatric surgery but a VLED may also be followed with appropriate food choices in place of or in addition to shakes.


The main aim of the VLED is to prepare the liver for surgery and thus reduce surgical complications.
A large proportion of the Bariatric community (up to 50%) can have what’s termed as a ‘Fatty liver”.

The liver stores both fats and sugars which in turn cause it to be “fatty”. A fatty liver is large and may be prone to bleeding and this increases surgical risk.

A VLED will facilitate liver shrinkage, and reduce bleeding tendency thus making it smaller and easier to retract (lift out of the way of the stomach) during weight loss surgery.

The VLED also has other benefits, these include

  • Weight loss – great to get started and lose some weight prior surgery -let the journey begin!
  • Improved biochemical markers including Blood sugar levels and insulin sensitivity, improved anti-inflammatory responses and clotting factors. All of which  relate to improved post surgical outcomes.
  • Can help you overcome the ‘Last Supper’ temptation to eat everything you may feel you will miss after surgery.

Just to clarify, the majority of people can tolerate most food again after surgery. It just takes a bit of education and time to learn what you can eat, and how much. Of course it will vary from person to person and be dependant on the type of surgery you have, but the foods to be aware of would be the sweet, rich and fatty foods. Eat with caution and moderation. But you should find once you have settled into your new stomach after weight loss surgery you should be able to tolerate almost everything in small portions.

HOW the VLED works

The VLED facilitates liver shrinkage via depletion of glycogen stores. As glycogen stores are depleted the liver becomes smaller and firmer and thus is easier to retract and less likely to bleed during surgery.

The restricted carbohydrate diet then causes the body to switch to burning ketones thus instigating a form of ketosis. Being in Ketosis helps reduce appetite and  cravings thus helping you to stay on track with the diet.

As mentioned VLED meal replacement products including shakes, soups or bars have traditionally been the main form of VLED. But careful food selection along with the meal replacements can be tailored to achieve the same results.

It is important that your dietitian calculates your nutritional requirements  and formulates an individualised plan just for you. If you have Diabetes or other health conditions these will be taken into consideration.
Factors such as protein requirements, amount of carbohydrate, vitamins and minerals requirements are all calculated and then a format decided.

Your personalised VLED may consist of some shakes and some low carbohydrate meals with low carb snacks added. Or it may just be a low carb meal and snack plan – 3 meals and 2 or 3 low carb snacks.

What ever format is decided it is important to remember to include;
– at least 2 cups of low carb veggies or salads per day
– drink at least 2 litres of water per day
– and add a source of healthy fat such as olive oil or nuts per day.

Sound confusing? Don’t worry your dietitian will help you calculate all of this and come up with a rock solid plan tailored just for you.

Some find the VLED challenging, but most when asked after surgery “how did you find your VLED?” say it was fine -even those who thought they would struggle! It’s a small step in the right direction for the next step of your weight loss journey.

The VLED is an important step in the Bariatric journey – discuss with your dietitian your individual requirements and then a plan can be designed to meet your nutritional needs, shrink your liver and start your weight loss journey.


Are you ready to find out more?

Call us today for a complimentary 30-minute consultation with our Bariatric Nurse Educator or one of our Bariatric coordinators.