Make a low-fat carrot-raisin salad by substituting orange juice for the mayonnaise or sour cream. Grate a few carrots while soaking raisins in orange juice; sprinkle a tablespoon of oil over carrots (optional). Add raisins and more orange juice if desired. Throw in some sunflower seeds and refrigerate for a few hours. (Linda Posell, Washington)

Store lemons in the indented ovals of the refrigerator door in place of eggs. Use as a staple for seasoning chicken, fish and other foods. Use dried red hot peppers to season stir-fried vegetables, spaghetti sauce and soup. (Linda Posell, Washington)

Make a Strawberry Angel Cake by topping a piece of angel food cake with strawberry frozen yogurt, fresh or thawed sliced strawberries and a tablespoon or two of raspberry liqueur. (Ellen Gordon Gordon)

Extend butter by combining 1/2 cup polyunsaturated oil, 3 tablespoons water and 1/2 teaspoon liquid lecithin (available at health food stores; it emulsifies the mixture) in a blender. Blend well, then add 1/2 pound very soft butter. Blend well. It extends 1/2 pound butter to nearly a pound. (Nancy Goldcamp, Vienna)

Use wheat germ in place of some or all of the bread crumbs your recipe requires. (Wendy Griswold, Arlington)

Make a "rich" milk by using two parts nonfat dry milk powder to three parts water. Use over cereal or mash with potatoes, some grated onion and a little salt and pepper. (Rosalie Wienhoff, Potomac)

For a higher-fiber peanut butter and jelly sandwich, substitute diced prunes or other dried fruit for the jelly. (Elaine Hodges, Adelphi)

When using low-fat yogurt in place of sour cream in stroganoff, add 1 tablespoon of cornstarch to keep it from curdling. (Marcia Sandground, R.D., Bethesda)

Debbie Mattes-Kulig, a registered dietitian from Falls Church, has the following specific substitution suggestions:

Butter: 1 tablespoon butter equals 1 tablespoon margarine or 3/4 tablespoon polyunsaturated oil. 1 cup butter or margarine equals 3/4 cup oil.

Chocolate: 1 ounce of chocolate equals 3 tablespoons dry cocoa powder plus 3/4 tablespoon polyunsaturated oil or 1 tablespoon margarine.

Cream cheese: Blend 4 tablespoons margarine with 1 cup dry low-fat cottage cheese. Add a small amount of skim milk, if needed, in blending mixture.

Eggs: 1 whole egg equals 2 egg whites or 1 egg white plus 1 tablespoon polyunsaturated oil.

Milk: 1 cup whole milk equals 1/2 cup evaporated skim milk plus 1/2 cup water plus 2 teaspoons oil OR 1 cup prepared nonfat dry milk plus 2 teaspoons oil OR 1/2 cup skim milk and 1/2 cup plain yogurt.

Salad dressing: Use half oil and half vinegar instead of 3 parts oil to 1 part vinegar. For a mayonnaise-based dressing, use 1 part yogurt for every 3 parts mayonnaise.

Sour cream: Aside from yogurt or low-fat cottage cheese blended until smooth, whip one can of evaporated skim milk with 1 teaspoon of lemon juice.

Sugar: Use 2/3 to 3/4 of the sugar called for in the recipe.

Whipped topping: Nonfat dry milk or canned evaporated skim milk can be whipped. Chill the bowl and beaters; add the chilled milk, whip until stiff, add sweetening and flavoring and serve immediately.