LADY 2: Janet just got out of Rainbow Hills two days ago.
LORELAI: Rehab?
LADY 1: Fat farm.
Even though a “fat farm” sounds like a place you go to in order to gain weight, it’s actually an old fashioned word for a residential weight loss program. It seems like a word they would use on a sit-com from the 1970s – Oscar and Felix from The Odd Couple went to a fat farm in one episode. Why is everything so dated in the world of Gilmore Girls?
The Hartford debutantes seem to be going to extremes for their debut, enrolling in weight loss programs, like Janet, and getting nose jobs, like Libby. Lucky Rory already looks perfect, so she doesn’t need to do anything except show up.
The Annotated Gilmore Girls 