When McDonald’s announced earlier this year that it would allow customers to add an extra burger or six chicken nuggets to an order for a dollar, it was an affirmation of its long-standing identity as a place to go out to eat cheaply and efficiently. It’s an image that has served it, and the fast-food industry more generally, well at a time when more expensive restaurant chains are buckling under a lack of business and filing for bankruptcy.

In fact, the drive for ever-greater efficiency and lower costs is characteristic of the fast-food model, right down into its supply chains. As historian Patrick Dixon writes in his book Nuggets of Gold: Further Processed Chicken and the Making of the American Diet, menu items like chicken nuggets didn’t come about because people asked for them. They were the result of decades of scientific and industrial innovations to get more food out of less chicken — and more labor out of the people who processed them.

For Jacobin, Alex Park interviewed Dixon about the history of this peculiar culinary innovation. They discussed the origins of “further processed chicken,” what it tells us about the political economy of fast food, and the brutal labor conditions behind chicken nugget production.