Sure, why not? Guy taking the order would just say, "Your total comes to $18.95 and 3462 calories. Have a great day." Who wouldn't want to hear that? Then, they could do one of those promotional things where if they forget to tell you, you get a free order of bread sticks or soda or something.
Hmmmm. Not as totalitarian as making Failure to Disclose Caloric Content a felony, but we can always work up to felony later...