How The Cast Of 'It's Always Sunny In Philadelphia' Aged Throughout The Show

Rob McElhenney was 28-years-old in 2005 when Always Sunny first premiered. In the latest season, McElhenney was 47. Throughout the long-running series, the character of Mac has undoubtedly undergone the most physical changes.

Rob McElhenney, who plays the character Mac, decided that a sudden weight gain would be a great way to mock other shows where the actors seemingly become more attractive through the seasons. He was 34 at the time. As he explained to The Wrap:

“Yeah, I was jolly as f—. And I was just full of energy, because I was eating so much. It was just constant fuel.”

Mary Elizabeth Ellis first appeared in the series as The Waitress when she was 26. While she's a brunette at the age of 26 in the first season, her style evolves from coffee shop chic to a more sophisticated (and blonde) look. In the most recent season, Ellis was 45.

Though she despises Charlie on the show, in real life, Ellis and Charlie Day are married:

“It’s fun when people find that out [that we're married in real life] and they’re really excited.”

Glenn Howerton was 29-years-old during season one of Always Sunny. In the most recent seasons, Howerton was 49. Since his Always Sunny fame he's been in many acclaimed series and films such as Blackberry, A.P. Bio, and The Mindy Project.

When season one first premiered in 2005, Kaitlin Olseon was 30. In the most recent season, Olson was 49. As Kaitlin Olson has explained of her character Dee Reynolds:

"Dee absolutely hasn't changed. That's kind of the goal for us, to make sure these characters age, but don't ever grow or change. […] As they get older, they'll be the same people who never learn a lesson. I love the idea that absolutely no growth has happened in these characters."

In real life, Olson and Rob McElhenney secretly began dating in 2006:

"We were very sneaky at first because we thought, This is a really bad idea. But then I fell in love with him."

When Danny DeVito joined the cast in season two, he was 62-years-old. In the most recent season, DeVito was 80. Danny DeVito remains a hugely popular figure in Hollywood, making a name for himself back in the '70s with Taxi.

Charlie Day was 29 when the show started in 2005. In the most current season of the series, Day was 48. He has since starred in films like Horrible Bosses and Pacific Rim.