An experiment so bold, anyone might think it's a little crazy...

Catherine Locke is smart, ambitious, and--okay, not the slimmest girl around. But she's always cared more about her brain than her body. So far that's gotten her where she wanted: into the most advanced, competitive science class at her high school, where she'll once again face her fiercest rival, Matt McKinney.

The guy who broke her heart.

If Cat's plan works, she'll win it all: a huge improvement in her body and her lifestyle, first prize at the science fair, admission to the college of her choice, and best of all, revenge on Matt McKinney.

But as every scientist knows, even the best experiments can go wildly out of control...

"Fat Cat was AWESOME. I couldn't stop reading it!" Meg Cabot, New York Times bestselling author of The Princess Diaries & more

*Named Best Fiction for Young Adults by the American Library Association