I always make my shakes with 450ml of ice cold water plus 6 large ice cubes and put them in the blender. That way they come out a bit like a frappe and you really feel you have had a treat.
I am right off the soups but when I do have them I mix them with 450mls of water and add some herbs as they are quite bland. That gives a good portion.
Whatever I have, I always drink half a litre of water straight after and I find that helps to fill me up.
Hope that helps - and all the best with your CD journey!
x