Preheat waffle iron according to manufacturer's instructions.
Beat egg whites in a glass or metal bowl using an electric mixer on high until stiff peaks form. Lift your beater or whisk straight up: the egg whites will form sharp peaks.
Whisk flour, cornmeal, chia seeds, baking powder, baking soda, white sugar, and salt together in a bowl.
Whisk buttermilk, canola oil, and egg yolks together in a separate bowl; stir into flour mixture until batter is smooth. Gently fold egg whites into batter until just mixed.
Pour about 1/4 cup batter into preheated waffle iron; cook according to manufacturer's instructions until golden brown, about 5 minutes. Repeat with remaining batter.