It seems like all my favorite comedians have become Dads. Not too surprising for men of a certain age, although stand-up comedy is hardly a family friendly profession. The acts of Patton Oswalt and Brian Posehn, which were once nothing but nerd material about Star Wars and comic books, are now loaded with stories about their children, but neither come close to Jim Gaffigan and his five kids. I respect these men for being involved fathers, but I can't pretend I find parenting stories terribly funny.
Gaffigan's comedy has always been about the minutiae of daily life. He can talk about cake for 20 minutes and still be funny. His best material is self deprecatory and as the title Dad is Fat implies there is a lot of that here. Parenting humor tends to tread the same paths over and over: don't take your kids on a plane, don't try to eat at a fancy restaurant with kids, it's hard to get kids to go to bed. Gaffigan tells these same stories, but the size of his family makes everything more exaggerated and his skills as a storyteller keep you engaged.
Like most modern comics, Gaffigan's material is heavy on sarcasm, but given the subject matter he is at pains to remind readers that he is only kidding and really loves his family, mostly.