The science-experiment part of the tale is a bit of a gimmick it morphs from science fair to social science once Cat gets cute enough to attract boys. Part fat-girl-slims-down book, part advertisement for the real-food movement and part love story, this novel chronicles the many changes in Cat’s life as she goes from stout to scorching. Cat will live a prehistoric lifestyle, which involves walking everywhere, avoiding technology and eschewing processed food. To win the science fair, get revenge on a boy and become her true self, Cat, a hefty high-school student, decides to be her own experiment.