Rob McElhenney Wanted the Rest of the ‘It’s Always Sunny in Philadelphia’ Cast to Cultivate Mass With Him During the ‘Fat Mac’ Arc

If Rob McElhenney had his way, Ronald “Mac” McDonald wouldn’t have been the only supersized member of the Gang.

Back in 2011, McElhenney began one of the most remarkable, lauded and entirely unnecessary physical transformations in the history of sitcoms during the off-season between It’s Always Sunny in Philadelphia Seasons Six and Seven. Over a period of three months, McElhenney amassed roughly 60 pounds of body fat on a steady diet of Krispy Kreme donuts and melted ice cream, thus launching the “Fat Mac” arc that would only be matched in terms of outrageous reshaping by the “Jacked Mac” storyline that came many seasons later. McElhenney’s sheer commitment to a simple, stupid but entirely hilarious bit paid off with one of the best-ever seasons of Always Sunny and, therefore, one of the greatest years for sitcoms in human history.

But as McElhenney explained to fellow TV comedy giant Nick Kroll back in a conversation for Reuters hot off the swollen heels of the “Fat Mac” arc in late 2011, the original idea for the bloated bit would have required the entire Always Sunny cast to tack on mass alongside McElhenney. Unfortunately for the show (and for Krispy Kreme), the plan fell apart when McElhenney’s castmates refused to cultivate that much cholesterol.

According to Reuters, McElhenney reported that “he tried to get the whole cast to join in the weight gain, but all passed,” with the most notable veto coming from inside the McElhenney-Olson household. “His wife, Kaitlin Olson, was especially uninterested after having their first child last year.”

However, as McElhenney reported, the rest of The Gang didn’t know what they were missing. “I never felt lethargic. I felt great. I felt fucking great,” McElhenney said of his new size, attributing the burst in energy to the constant intake of food that characterized three months of his life. But more than that, McElhenney said that putting on that much weight made him more confident than he’d ever been in his comedic abilities. “I feel like for the first time in my life I’ve been watching the show like, ‘All right, I’m almost as funny as everybody else,’” McElhenney admitted of how Fat Mac stacked up against the rest of The Gang.

So, for that reason, maybe it’s best that Olson, Glenn Howerton, Charlie Day and Danny DeVito weren’t down to pack on 60 pounds, as McElhenney may have felt even more insecure if he thought that Doughy Dennis or Chunky Charlie were even funnier at being fat than he was. And, thankfully, the joke landed spectacularly — through his massive transformation, McElhenney mocked the trend in sitcoms that every single character, with increased makeup budget and access to expensive skin treatments, inevitably grows more groomed and attractive as time goes on. 

“Even the nerds on Big Bang Theory are getting better looking,” McElhenney said of the boring upward trajectory in comic attractiveness. “Their clothes are getting nicer. They’re better groomed. It works for them. But this show — it’s not like that.”

Of course, that all went out the window once McElhenney decided to get massively ripped for Always Sunny Season 13, yet another transformation in which his wife wouldn’t join him, though not for lack of trying — Dee was scarfing down those steroids faster than Mac could eat a garbage bag full chimichangas.