I remember reading somewhere that the tradition of the Great Lent originated from the act of compassion of members of early Christian communities. Since the very first years of Christianity, there was a custom to baptize new converts on Pascha. Before their baptism, they had to fast. Other people in congregations, those who had already been baptized, decided that they should support the new members and fast, too.
And it really does make a difference. My husband, a meat-and-potatoes guy who is tofu-phobic and never met a vegetable (except green beans and corn!) that he liked, says the thing that keeps him going through the fast is knowing that we're all in this together!