Cat is funny, smart, and a little bit sarcastic--but she's fat and she's had enough of the teasing and the ridicule, especially by her ex-double-crossed-best-friend Matt McKinney. That's where her science project comes in: as her own experiment, Cat is going to go back to humanity's roots (the hominids) and change her lifestyle completely. Watch out Matt McKinney, the new and improved Cat is coming in! I loved seeing Cat's classmates' reactions to her "after" phase, though I don't agree that girls have to be "skinny" to be "happy" and "popular". This book gives a slightly different dimension to it, however, by focusing less on the "skinny" and more on the "healthy". Despite its predictability, I still think that Fat Cat was overall a book worth reading. Girls who are looking for a humorous read and a spunky, slightly insecure (okay, make that REALLY insecure) main character would love this book. Anyone above 8th grade would relate to this book the most, and would probably get the most out of it.