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August 1, 2026Short & citedBlog
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Everyday Life • Food & Drink

The DUFF

The DUFF is a 2015 American teen comedy film based on Kody Keplinger’s 2010 novel of the same name.

Updated August 1, 20261 min readCited sources

The DUFF is a 2015 American teen comedy film based on Kody Keplinger’s novel. The title stands for 'Designated Ugly Fat Friend,' a slang term for the less attractive friend in a group.

What is the DUFF?

The acronym DUFF stands for 'Designated Ugly Fat Friend,' a rude label for the perceived least attractive person in a friend group. The term gained wider recognition through the 2010 novel and 2015 film, but it remains derogatory even when used jokingly.

Plot and premise

The film follows high school student Bianca, who discovers she has been labelled the DUFF by her peers. She responds by challenging social hierarchies and rethinking popularity, identity, and self-image—a classic teen comedy arc with a modern slang twist.

Book vs. film

The film is an adaptation of Kody Keplinger’s 2010 young adult novel. While both share the same basic premise—a teen labelled the DUFF—the movie changes details, pacing, and some character portrayals to suit the screen. Fans of the book will find the core idea intact but not a word-for-word copy.

In short

  • The DUFF is a 2015 teen comedy film based on a 2010 novel.
  • The title acronym means 'Designated Ugly Fat Friend.'
  • The story confronts social labels and popularity culture.
  • The book and film differ in adaptation details.
Canadian angle

The term appears in Canadian English through youth culture, online slang, and North American teen media. Canadian readers may also encounter it in discussions of body image, social labels, and school-life comedy films.

Quick questions

What does DUFF stand for?
DUFF is slang for 'Designated Ugly Fat Friend,' a rude term for the less attractive friend in a group.
What is the Duff movie about?
The film is about a high school student who learns she has been labelled the DUFF and tries to change how others see her.
Is the Duff book different from the movie?
Yes. The film follows the novel’s premise but changes some details, scenes, and character choices in adaptation.

Sources

  1. Dictionary.com — https://www.dictionary.com/culture/slang/duff
    Supports: Defines DUFF as the slang acronym “designated ugly fat friend.”
  2. Dictionary.com — https://www.dictionary.com/browse/duff
    Supports: Provides other established meanings of duff in English, showing the term is polysemous.
  3. Merriam-Webster — https://www.merriam-webster.com/dictionary/duff
    Supports: Lists standard dictionary meanings of duff, including pudding and informal senses.
  4. Wiktionary — https://en.wiktionary.org/wiki/DUFF
    Supports: Records DUFF as a slang acronym for “designated ugly fat friend.”
  5. Wiktionary — https://en.wiktionary.org/wiki/duff
    Supports: Lists multiple meanings and senses of duff across English varieties.
  6. FastSlang — https://www.fastslang.com/duff
    Supports: Explains DUFF as “Designated Ugly Fat Friend.”