Jason Segel Tells 'Late Show' That Studio Head Forced Him To Lose Weight For 'The Five-Year Engagement' (VIDEO)

A svelte Jason Segel stopped by "Late Show" (Weeknights, 11:35 p.m. ET on CBS) to promote his latest movie, "The Five-Year Engagement" and he revealed the secret behind his new look.

"I was forced to lose weight for this movie," he said. When David Letterman asked who made him do it, Segel laughed: "the studio president!" That would be Universal President Ron Meyer.

So, how much did he drop? "A good 35 lbs," Segel said. Not easy when you're playing a chef and have to eat on-screen, but the studio provided him with a personal trainer on-set who monitored his diet and exercise.

However, Segel said, he managed to cheat on his regime by eating extra mouthfuls during takes.

"The Five-Year Engagement" is in theaters Friday, April 27. "Late Show With David Letterman" airs weeknights, 11:35 p.m. ET on CBS.

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