The story revolves around Sherman Clump, a college professor struggling with his weight, as evident from his fridge filled with diet products promoted by a fitness guru. Despite his efforts, the products are ineffective.

Sherman's professional life is chaotic when he discovers that his test subjects—hamsters—have escaped their cages, causing havoc on campus. His assistant, Jason, is alarmed to report that all the cages were left open, revealing that Sherman's large frame inadvertently triggered the switch when he turned around. The only hamster that didn’t escape is Shelly, who is too big to move.