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.
Calorie is referred to as a unit of energy, which measures the amount of energy derived from consuming the food you eat. A majority of fruits has high quantities of water and the calorie content comes from the presence of fructose (fruit sugar). Oranges have around 85% of water and low levels of calories. One medium sized raw orange contains 62 calories, as per the USDA Dietary Guidelines. A cup of freshly squeezed orange juice comprises of 112 calories, while a cup of unsweetened canned juice has 105 calories.