Cons
It can make social situations difficult. Surviving on a diet that requires you to eat only certain products can feel socially isolating as you will be unable to join in with any food-related social activities.
You will miss real food. Apart from the fact that you won’t be eating any solid food, the ingredient lists for the shakes and soups are as long as your arm. In the Oriental Chilli flavour soup you have to read quite far down before you get to dried red peppers or anything that sounds like a real ingredient; skimming past things like maltodextrin, powdered cellulose, potassium chloride, soya lecithin and hydrolysed maise protein. Yum.
Dieters have reported all sorts of side effects to VLCDs, including fairly common ones such as headaches, tiredness, dizziness, nausea and diarrhoea and more worrying ones including hair loss, skin rashes and gallstones.