Demand for convenience foods has grown in the United States, which has implications for dietary quality and health, but little is known about the drivers behind the growth in purchases of such foods. We construct a novel data set that contains price indexes, budget shares, advertising expenditures, and demographic and time variables for four Census regions between 1999 and 2010 for six types of convenience foods, including 4 food-at-home categories—basic ingredients, complex ingredients, ready to cook and ready to eat—and 2 food-away-from-home categories—fast food and sit down. We use these data to model demand for convenience foods using the almost ideal demand system, and then use the estimates to decompose growth in demand for convenience foods into price, advertising, demographic and time factors.