Over the past four decades, demand for foods that save households time in meal prepa - ration and cleanup (i.e., “convenience foods”) has grown in the United States. This has implications for dietary quality and health. But little is known about the drivers behind the growth in demand for such foods. One driver might be that Americans are purchasing more processed foods because of those foods’ declining market prices rela - tive to their less processed counterparts. Another driver might be that the most adver - tised foods are those that are the most convenient or that American households have little time for meal preparation because of labor-market participation. How declining incomes affect the demand for convenience may also be a driver. Between 1999 and 2010, changes in prices and total food expenditure drove most food-purchasing patterns. Meals and snacks at fast-food restaurants were also responsive to changes in advertising expenditures, while hours worked had little effect on demand for any foods.