What is the origin of the idiom "couch potato" and when to use it?

The term "couch potato" came into use in the late 1970s and early 1980s. It plays on the image of a potato plant, which remains static in one place and passively absorbs nutrients. It refers to someone who spends much of their free time lounging on the couch in an inactive state, often while watching television or screen-based entertainment. It describes a sedentary lifestyle characterized by excessive inactivity and lack of exercise due to excessive time spent engaged with media sources from a horizontal position.