Diary of a Wimpy Kid: The Ugly Truth

Diary of a Wimpy Kid: The Ugly Truth is a 2010 bestselling children's fiction book by American author and cartoonist Jeff Kinney and is the fifth book in the Diary of a Wimpy Kid series. The Ugly Truth sold 548,000 copies in its initial week of publication, edging out Decision Points, which sold 437,000 copies.

Kinney initially struggled with the decision of whether Greg would be a non-aging "cartoon character" or a literary character that would age and go through puberty, deciding to make puberty one of the book's themes. Kinney also debated over whether to end the series with five books, eventually deciding to continue the series.

Summary
Greg explains that since his and Rowley's fight in the previous book, their friendship is history. Greg's mother Susan goes back to college to stimulate her mind and the Heffley men must take care of themselves. Food is often ruined and Greg is short of clean clothes. Greg's father Frank makes Greg responsible for waking himself up. Greg puts his alarm clock under his bed, but the ticking sounds like a bomb and he cannot sleep. He accidentally activates the school fire alarm and the school closes early. Frank is not happy to be called from work to pick up Greg.

A maid, Isabella, arrives to help with the kids after school. She spends her time watching television and eating snacks. Greg finds her sock in his bed, showing she has been napping there. Frank takes Greg to his dentist, and Greg accidentally bites his finger resulting in him being prescribed headgear for his overbite. The next day, Greg loses his headgear then finds Manny wearing it. Greg vows not to wear the headgear.

At the school lock-in Greg is shocked that 90% of the crowd is boys. Mr. Tanner confiscates their cell phones. At 3:00 AM some parents arrive to take their kids home because they did not answer their cell phones, leaving Greg and Rowley behind. The next week, Greg becomes sick from lack of sleep and Susan leaves him with Isabella. He is awoken by noise from downstairs; Isabella has invited all the neighborhood maids to watch soap operas. Susan arrives home early and fires her, pleasing Greg. Rowley has a pimple on his forehead, and tells Greg he's "becoming a man". Susan and Frank talk to Greg about their experiences of being late bloomers. Greg writes a fake note to Rowley signed "The Girls" about no one liking his zit.

Jordan Jury, a popular kid in the grade above, invites Greg and Rowley to his party. However, Susan says he cannot go because his uncle Gary's fourth wedding is on that day. Greg worries about reading the Old Testament because adults think it's cute when a kid cannot pronounce a word. He is nervous about getting "The Talk" from his 95-year-old great-grandmother, He hears Susan talking about picking up "Greg's tuxedo", and is thrilled thinking he's going to be a groomsman. At Gammie's, Greg has to sleep in a crowded room with all the family's bachelors. He sneaks out and sleeps in the bathroom, waking just in time before Gammie comes in for a bath.

Before the rehearsal dinner, Greg describes how old and valuable her belongings are. He says he ate some old taffy once and got sick; he later saw a photo of his father eating the same candy when he was Greg's age. He discovers to his dismay he will not be a groomsman, but an assistant flower boy to Manny. Uncle Gary's best man Leonard gives a speech about how Uncle Gary and Sonja got engaged: at a baseball game, Gary was about to break up with Sonja so he could date her sister, but an airplane with a banner reading "Marry me Sonja?" - not meant for Gary's Sonja - coincidentally flew over the stadium and Sonja reacted to it. Sonja is upset and Greg thinks they will soon divorce.

Greg gets "The Talk" from Gammie. She talks about how getting older is not all it is cracked up to be. Upon returning to school, Greg learns that he dodged a bullet – Jordan only invited Greg's grade to his party to use them as servants. Greg and Rowley go back to being friends when Greg chooses to make a difference instead of just waiting for Rowley to come to him.

Reception
Critical reception for The Ugly Truth has been mostly positive, with the book gaining praise from the Los Angeles Times and the National Post. The School Library Journal gave a positive review for the entry while Common Sense Media commented that the book was not as "fresh and irreverent" as its predecessors.