When I had my wisdom teeth out 10yrs ago, I too had to do the liquid diet. I think the key here is not to drink high calorie/fatty milk shakes and stick to fruit smoothies, and soups.
Follow the drs. instructions to the T - do drink with a straw!!! I did and I got dry socket, my gosh, the pain of that was unreal. So I say for this week dont fret about the wt, let your body heal and then get back to your wt loss eating once your healed up.