I'd hate being restricted to 800 calories let alone being on an all liquid diet.
Let alone for 5-6 months.
Fortunately this is a very black and white program...no gray areas.
The "Ketosis Diet" is an all liquids diet until you get to your goal weight, only consuming 800 calories a day tops...that's about a pound a day loss for me in just calories. No food, not until the transition phase....and no exercise for the first couple months, because you simply aren't consuming the calories for your body to process. You will only break down muscle...not build any.