Kiwis and oranges are naturally low in calories and loaded with beneficial nutrients. Both fruits originated in Asia, but can be grown in various regions throughout the U.S. Oranges, as well as kiwis, grow anywhere that has ample sun, such as California and Florida. Peak season for oranges is winter, while kiwis peak in the late fall. Although both of these fruits have some similarities, their nutritional content can vary.

Oranges provide more calories per fruit, but this is mainly because oranges are larger. An orange that is a little less than 3 inches in diameter, weighs about 140 grams and provides 70 calories. A 2-inch kiwi, weighing 70 grams, has only about 45 calories.

Calories in kiwis and oranges come primarily from carbohydrates, but they do have trace amounts of fat and protein. An orange contains a little more than 17 grams of carbs, while a kiwi has 10 grams. Carbohydrates provide 4 calories per gram, totaling 68 calories from carbs in an orange and 40 calories from carbs in a kiwi.

Kiwis and oranges are both rich in vitamin C. This important vitamin keeps your immune system strong, improves blood flow and aids in wound healing. Both fruits provide about 70 milligrams of vitamin C, almost all of the vitamin C you need for the entire day. Women require 75 milligrams, while men need up to 90 milligrams.

Your body uses fiber to help pass through digested food, keeping your bowel movements regular. The soft parts of kiwis and oranges contain soluble fiber, while the tough, fibrous textures are full of insoluble fiber. While both types are equally important, they each play a different role. Soluble fiber soaks up water, creating a gel-like substance that slows digestion. Insoluble fiber stays intact and sweeps through the gut, creating a bulkier stool. A kiwi provides 2 grams of fiber per fruit, while an orange has 3 grams. You should consume about 14 grams of fiber for every 1,000 calories you have in your diet, suggests Colorado State University. For example, if you follow a 2,000-calorie diet you need 28 grams of fiber per day.