The most obvious explanation is that they were making a joke by picking the most greasy, unhealthy thing they could think of and had no real desire to go to KFC

The most obvious explanation is that they were making a joke by picking the most greasy, unhealthy thing they could think of and had no real desire to go to KFC. "What are you going to do with your new heart?" "Clog it up just like the last one. duh."