According to Self, one medium apple has 0.5 grams of protein. Though it's not a significant source of this nutrient, it's nourishing in other ways. For instance, that 3-inch diameter apple has 25 grams of carbohydrates but only 0.3 grams of fat.
The apple also has 4 grams of fiber, which is 17 percent of the recommended daily value. It also provides 14 percent of the vitamin C an adult needs for the day. There are 19 grams of sugar in a medium apple. Small amounts of vitamin A, iron and calcium are also present. A medium apple has a total calorie count of 95.