Thanks for the thought-provoking question, friend Lauren. According to this site:
http://www.endicott-studio.com/rdrm/rrMilkHoney4.htmlbread is first thought of as a symbol for the body. The most famous example to Christians is the Eucharist, or the bread which is consumed in Holy Communion and stands for the body of Christ. A related meaning is that of metamorphosis, since the grain is transformed into bread. The grain is milled, or ground between stones and thus undergoes a transformation which, although violent, renders it flavorful and nutritious and life-giving to humanity.
In the story of
Brokeback Mountain, Jack returns from his aerie where he watches the sheep during the day and eats two of Ennis' stone biscuits. In the movie, this symbolism is replaced by the Wonder Bread and, perhaps, the cherry cake and apple pie. There's another reference to bread which occurs way, way at the very end of the movie. It's a delightful and hope-filled message. Ennis stands before the closet and softly says, "Jack, I swear" to the shirts hanging there on a nail. He then closes the door, and we are left with a view of a blue light and a window through which we see the blue sky, the brown earth, and a green field. That field, as I'm sure you know first-hand, friend, is a field of barley, the grain from which bread, or even more likely, beer is made.