In a large mixing bowl, combine the flours, baking powder, baking soda and sugar.
In a medium bowl, whisk together the buttermilk and whole egg. Add to the flour mixture and stir to mix evenly.
In a large metal or glass bowl, using an electric mixer on high speed, beat the egg whites until stiff peaks form. Gently fold the egg whites into the flour mixture.
Place a baking sheet in the oven and heat to 225 F. Preheat a waffle iron. Spray with cooking spray if needed. Spoon or ladle about 3/4 cup of the batter into the waffle iron, depending on the size of the iron. Spread slightly with a spoon and cook according to the manufacturer's instructions. Transfer the waffle to the baking sheet in the oven to keep warm. Repeat with the remaining batter to make 6 waffles.