Often the determining factor is not how quickly your body recovers, but how quickly your mind recovers, since you temporarily will have lost your main training goal. Your eating after also should mirror your eating before, since a diet high in carbohydrates can help refuel your muscles as well as fuel them. Keep moving and start drinking, preferably a replacement drink such as Gatorade. Research suggests that refueling works best if done immediately after exercise, when the body is eager to absorb energy. As soon as your stomach can tolerate food, start eating.
Most marathons provide bananas, yogurt and other easily digested high-carbohydrate foods.
These are good for you. A long walk to your car or hotel room won't hurt you. After that, get off your feet and rest an hour or two. By then, you should be ready for more solid food. It too should be high in carbohydrates.