'The DUFF' by Kody Keplinger is worth reading even if you've watched the movie

The book cover for "The DUFF" is on the left (Poppy), and the movie poster is on the right (CBS Films).

"The DUFF" by Kody Keplinger is the inspiration for the 2015 movie of the same name. But the plot of the novel, while similar in spirit, is wildly different.

In the movie, Bianca (Mae Whitman) is told by her former childhood friend Wesley (Robbie Amell) that she's the "Designated Ugly Fat Friend" of her friend group, the person who people talk to in order to gain access to her prettier and more popular friends.

Bianca then receives his help getting a makeover so she can ask out her guitar-playing crush Toby (Nick Eversman) while avoiding mean girl Madison's (Bella Thorne) attempts to thwart their efforts. Toby then turns out to be "DUFFing" Bianca to get to her friends and Bianca ends up realizing she has feelings for Wesley.

In the novel, Bianca and Wesley aren't childhood friends and a lot of the plot focuses on them being enemies with sexual benefits. Also, Madison doesn't exist and Toby is actually a kind, nerdy boy who ends his relationship with Bianca amicably and compares their situation to "Wuthering Heights."

And while in the movie Bianca has a supportive functioning alcoholic for a mother, in the novel Bianca's mother is absent and sends divorce papers to her father, which causes him to relapse into alcoholism and become abusive until he goes back to Alcoholics Anonymous.

Despite the differences, I still appreciate the movie because it's similar in spirit and uses the same actress that Keplinger always pictured for Bianca.

I also appreciate how the movie added a lot of fun elements to the plot that maintained the quality of the movie even when the story differed from the book. The addition of Ken Jeong's character in particular was a highlight of the movie, as was the increased empathy and likability of Wesley.

One thing that sets the book apart from the movie is that it was written by a then 17-year-old Keplinger, so it accurately captures the teenage perspective in a way that can't necessarily be replicated by movie studios. As much as I liked the movie, the way the plot was changed and the insertion of characters like Madison feels pretty formulaic.

Overall, whether you've watched the movie version of "The DUFF" or not, I suggest reading the book that inspired it as well.