Rob McElhenney’s transformation on It’s Always Sunny in Philadelphia from Fat Mac to Jacked Mac is well-worn terrain. That transformation eventually culminated in the Mac Dance, one of the best and most surprising sequences in thirteen seasons of the series.
The reality, however, is that there wouldn’t be a Jacked Mac without a Fat Mac, because some of what Rob McElhenney did in transforming into Fat Mac laid the groundwork for becoming Fat Mac, as McElhenney explained to Dax Shepard in a recent Armchair Expert podcast with Dax Shepard.
First, here’s the origins story of Fat Mac: Ahead of the 2011 season of It’s Always Sunny, Rob McElhenney was editing an episode. During the course of that episode, he saw himself in a shot and thought, “That’s not a good angle of me,” and considered finding a different shot that made him look better. McElhenney’s vanity, however, inspired an epiphany. These characters are gross and disgusting and should be aging as people in their situation might age, he reckoned. It’s important, he thought, that everyone on the show look as disgusting as possible so that it would be more realistic. So, he pitched the idea of gaining 50 pounds to the entire cast. “DeVito is the only one that agreed, and I was like, ‘No. Not you. You’ll die.'” After everyone else rejected the idea, however, McElhenney asked if it was OK if he did it. “Sure,” they said.