1 cup whole-wheat flour
1 cup all-purpose flour
1 1/2 teaspoons baking powder
1/2 teaspoon salt
1/4 teaspoon baking soda
2 cups nonfat buttermilk
1 large egg, separated
1 tablespoon canola oil
1 tablespoon vanilla extract (optional)
2 large egg whites
2 tablespoons sugar

1. Stir whole-wheat flour, all-purpose flour, baking powder, salt, and baking soda in a large bowl. Whisk buttermilk, the egg yolk, oil, and vanilla (if using) in a separate bowl. Add the wet ingredients to the dry ingredients and stir with a wooden spoon just until moistened.
2. Beat the 3 egg whites in a grease-free mixing bowl with an electric mixer until soft peaks form. Add sugar and continue beating until stiff and glossy. Whisk one-quarter of the beaten egg whites into the batter. Fold in the remaining beaten egg whites with a rubber spatula.
3. Preheat a waffle iron. Brush the surface lightly with oil. Fill the waffle iron two-thirds full of batter. Cook until the waffles are crisp and golden, 5 to 6 minutes. Repeat with the remaining batter, brushing the surface with oil before cooking each batch.

Makes 6 servings.

Per serving: 241 calories; 4 g fat
(0 g sat, 2 g mono); 37 mg cholesterol; 41 g carbohydrate; 11 g protein; 3 g fiber; 450 mg sodium; 285 mg potassium