I have tried lowering the calories by substituting low fat milk or yogurt and the result is a curdled mess once the soup comes to a simmer. I read this tip in Cooking Light and it's a great way to lighten up those creamed based soups.
They suggested using brown rice to substitute for the cream. It seemed a bit strange but when the brown rice is overcooked in a broth and then pureed with low-fat milk it works. The brown rice becomes a rich, nutty cream that not only thickens but also adds a velvety-smooth mouth feel with only 7 calories and no sat fat per tablespoon.
Here's the Formula
Bring 2 cups unsalted chicken stock and ½ cup uncooked instant brown rice to a boil in a small saucepan over medium-high heat. Cover, reduce heat, and simmer 25 minutes. Remove from heat; let stand 5 minutes. Blend mixture and 1 cup, 1% low-fat milk in a blender until smooth. Makes 3 cups.
Try this next time you are tempted to make that cream base soup. It will make you a believer.
Cooking Light Brown Rice Cream
107 calories 1.3g fat 0.5g sat fat per cup