You'll also want people to RSVP so you have a head count for the caterer. If, on the other hand, your rehearsal dinner will be fairly low-key or small (think: a party at a restaurant or an intimate gathering at your future in-laws' home) then you don't need to be as official with your invitations.
The exact nutritional value of an orange depends on its variety. According to the U.S. Department of Agriculture, a standard-sized navel orange contains 69 calories, 17.6 grams of carbohydrates and 11.9 grams of sugar.
All types of orange juice yield about 110 calories per 1-cup serving. They all have about 21 g of sugar per cup, 12 g of carbohydrates, a nominal amount of fat -- less than 0.1 g -- and about 0.5 g of dietary fiber. Fiber content may increase depending on the presence of pulp.