A runner must eat according to the same recommendations made for the rest of the population. He/she should simply eat his/her fill and have a varied diet.
Remember: There is no miracle food. So the key for a healthy runner’s diet is for him/her to eat a variety of foods in order to store the fuel needed for his/her training, and the nutrients necessary for the proper functioning of his/her body. In other words, eat so the body can “help itself”, as needed with fuel and nutrients.