All eating is functional. Go long enough without eating and you will die.
True Adonis, while you are 100% correct regarding this assertion, would you say that professional athletes are more careful about their diet compared to the average person? For example, marathon runners will load up on carbs because it serves a purpose. The average person isn't eating carbs for a very specific reason, like a marathon runner. It would seem obvious that professional athletes definitely eat certain foods because they serve a very specific purpose when compared to the average person who just eats to eat--although, at the end of the day, all foods serve a purpose, even if we are not consciously aware of its purpose.