Food menu legend consistency

Should a food menu legend have "Gluten Free" and "Contains Nuts" or would it be better to be consistent with "Gluten Free" and "Nut Free" or even "Contains Gluten" and "Contains Nuts."

Each of the menu items will be marked with the appropriate symbols.

I think there is a convention to prefer "Gluten Free" in isolation, and "Contain Nuts" in isolation, but mixing them seems rather strange to me.

This menu will be for US users if that matters.