The fattest kid in the fifth grade wants to lose weight, but not badly enough to starve.

Michael's diary reflects the ups and downs of his eleventh year, as he copes with braces, troublesome relatives, a little sister not yet potty-trained, the school play, and a big spelling bee.

Sixth grader Peter is pretty much the average kid: he likes gaming, hanging with his friends, and his beloved pair of Air Jordans. But when he has to give up his most prized possession -- his bedroom -- when his recently widowed grandfather moves in with Peter's family, he's unwilling to let such an injustice stand. Peter devises a series of increasingly elaborate pranks to drive out the interloper, but Grandpa Ed won't go without a fight.