How much weight on average can a person loose on a 2 week liquid diet?

My surgeon told me to expect to lose about a pound a day.

Another way to figure it out is this: how many calories do you normally eat in a day? If it is 2,000 cal and a liquid diet is on a average 800 cal you are taking in 1,200 less cal a day. A deficit of 3,500 cal loses one pound. So at that rate you'd lose approx a pound every 2-3 days. Of course if you are normally taking in over that, the pounds come off faster.