This Low Calorie "Secret" Burger Sauce is just 19 calories per tablespoon, and packed with healthy ingredients. I know you'll love this low calorie alternative. I used metabolism boosting greek yogurt as the base, it's super thick so you hav the option to make this yummy sauce as thick or as thin as you would like it. Special Tip: To lower the sodium remove the salt and add in 1/2 teaspoon lemon juice.