We apparently do not look as closely as we should when we go to the supermarket. One paragraph from this book review should be enough to know whether you want a closer look:

…Author Benjamin Lorr spent five years looking into that as he studied all aspects of American supermarkets — from the suppliers, the distributors, and supply routes, to the workers in the retail outlets themselves. In the reporting for his new book The Secret Life of Groceries: The Dark Miracle of the American Supermarket, Lorr met with farmers and field workers and spent 120-hours-straight driving the highways with a trucker as she made her multistate rounds. He worked the fish counter at a Whole Foods market for a few months, and went to trade shows to learn about entrepreneurs who were trying to break into the industry. He also traveled to Asia to learn about commodity fishing – finding human rights violations along his journey…

Antitrust considerations might be of interest if you plan to purchase The Secret Life of Groceries.