While most Americans view soup as a quick lunch item or long-simmered main course, soups are easy to make and are terrific first courses for people trying to lose weight. Broth-based soups fill you up without being high in calories or fat.
Low-Fat Substitutions
Here are a few tricks for upping the flavor of your soups while lowering their fat content:
• If your recipe calls for pre-cooked vegetables–such as onions, celery, or carrots–use a very small quantity of oil or cooking spray. If the vegetables start to stick to the pan, add a tablespoon or so of water, wine or broth to keep them from burning.
• Brown meats in a separate pan. Discard fat, and pat meat dry before adding to your stock pot.
• Miso–fermented soybean paste–adds savor to soup stocks, especially vegetarian broths. Add a tablespoon or so per quart of water, or to taste.
• Fry your spices for a minute or so over medium heat before adding them to your soup. Add dried herbs at the beginning of the cooking time, and fresh herbs right before serving.
• If your recipe calls for a heavy cream, use pureed cooked potatoes instead. Or remove about two cups of your cooked soup and blend until smooth. (Use a stick hand blender for best results, or puree it one cup at a time in a blender. Hold the lid on tight with a kitchen towel to protect yourself from burns.) Stir the puree back into the soup to thicken it.
• To add real cream flavor, stir in a few tablespoons of heavy cream when the recipe calls for 1 cup–a little cream will go a long way.
Note: because cream is an emulsion, it doesn’t “break” or curdle–like milk or sour cream can do–if the soup starts to boil. Use the real thing, but in small amounts, if you’re watching your saturated fat intake.
source: http://allrecipes.com/HowTo/Healthy-Soups/Detail.aspx