The author Mary Roach, in her book "Gulp: Adventures on the Alimentary Canal," describes the complex process of digestion that goes beyond just eating meals. She emphasizes that while men and women consume food, they are also taking in essential nutrients. This intricate process involves the transformation of food into a moistened bolus, which is pushed into the stomach through muscular contractions, where it mixes with hydrochloric acid.

Roach further indicates that the result of digestion leads to significant transformations, remarking that this process culminates in the creation of powerful social taboos surrounding food. Her metaphor of lunch as an "opening act" highlights that the journey of food doesn't end at the table; instead, it leads to larger implications for human culture and society.