Before surgery, many surgeons ask you to complete a strict meal replacement program for at least two weeks before your surgery date to shrink your liver's size and make surgery safer.
The products recommended are called Very Low Energy (or Calorie) Diets - VLED or VLCD for short.
My investigations, which were presented at Obesity Surgeons Society Australia and New Zealand in 2012, reveal that no meal replacement product available in Australian marketplace is nutritionally complete. The same is true in 2019. Read my detailed product review here. Some products are better than others but all need to be 'topped up" with something extra, and some people need to take even more care when using meal replacements.
Some manufacturers claim their products are complete but that is not really correct when judged against the Nutrient Reference Values for Australians and New Zealanders. Unfortunately, the Food Standards regulation that governs VLED products is out-of-date and reflects the older nutrient guidelines. Manufacturers must abide by these standing regulations which define what is permitted to be included and the levels for addition of vitamins, minerals and trace elements. The manufacturers are bound by the regulations and so can not make their products satisfy the current NRVs.
What does that mean for you?
I recommend that anyone using a meal replacement VLED product now a comprehensive multi-vitamin and mineral supplement. You need to speak with your own dietitian about which supplement is best for you; the choice is based on your age, gender, health and the product being used.
I also recommend that anyone who weighs more than 110 kg eat extra protein to supplement the indispensable amino acids that are essential for the human body. The final amount of extra protein also depends on the product being used and their body weight. Some products don’t need extra protein until a person’s body weight is 130 kg or more. But as a ball-park for anyone weighing more than 110 kg, the starting supplemental serve would be 1 cup diet/low joule jelly PLUS either 90 g ham or 90 g (raw weight) beef or pork or 1 egg. The low joule jelly (gelatine or collagen) is important for some specific amino acids!
Science and nutrition knowledge have come along way since the old nutrient guidelines and it looks like we will be waiting for some considerable time for the Food Standard to establish a revised standard for VLED products.
As always, this information is of a general nature only and you ought to discuss your needs with your own health professional team.