Do long distance runners usually eat alot?

i run 5-6 times a week and its usually anywhere from 4-8 miles, and sometimes i do work outs because i run xc and track. i also lift weights 2-4 times a week. but i eat soooo much, its like i am never full? is that normal that long distanece runners eat alot? why do i eat so much? i am 5'6 and weigh 108-115 it varies haha.