The share of home-cooked food in the diet of UK households declined from the 1980s. This was contemporaneous with a decline in the market price of ingredients for home cooking relative to ready-to-eat foods. We consider a simple model of food consumption and time use that captures the key driving forces behind these apparently conflicting trends. We show that observed behaviour can be rationalised by the fact that the shadow price of home-cooked food, which accounts for the fact that cooking takes time, has risen relative to the price of ready-to-eat food, due to the increase in the market value of time of secondary earners. We discuss the implications for policies that aim to encourage healthier diets.