What percentage of an elite athletes diet is carbs?

The human body does not need carbohydrates, they are non-essential. Because of this there is no amount of carbohydrates which you should consume.

But Vitamin C is an antioxidant which the body can't produce by it self. This vitamin is found in vegetables and in smaller amounts in fruits and berries. These foods do contain carbohydrates and unless you want to eat supplements you will have to eat certain amounts of carbohydrates in order to keep your body functioning correctly.

Parts of the human brain demands glucose in order to function properly. Carbohydrates supplies the body with glucose, which has caused people to believe that carbohydrates are needed. But the body can make glucose from protein and fat. This process is called "gluconeogenesis".