20 Things You Didn't Know About It's Always Sunny In Philadelphia
11. Rob McElhenney Tried To Convince The Entire Cast To Gain Weight For Season 7
In the show's seventh season, fans were introduced to "Fat Mac," but rather than simply don a fat suit for the season-long gag, Rob McElhenney actually gained 52 pounds of weight for real.
He achieved this by eating 5,000 calories worth of food per day in the lead up to production, with his appearance designed to satirise the tendency for sitcom cast members to become more fit and attractive as seasons progress.
Better still, McElhenney also attempted to convince his fellow cast members to join in and get fat, though every single one of them refused, especially his wife Kaitlin Olson, who had given birth to their first child just the year prior.
Nevertheless, McElhenney's commitment to the part is insanely impressive, and resulted in one of the show's most iconic and unforgettable gags.