Before singer Greg Lake was part of the band Emerson, Lake, and Palmer (ELP), he was the lead singer of another band called King Crimson. King Crimson’s first album had a dark tone, so for their second album, they opted for a slightly sillier tone. One of those songs on their second album was called Cat Food.
The basic idea behind the Cat Food song was that most processed foods sold in supermarkets today are nothing more than repackaged forms of cat food. So if you’re eating overly processed food, you might want to make sure you didn’t open a can of cat food by mistake.