Credit: Astrid Stawiarz/Getty Images; Jason Kempin/Getty Images Photo: Jason Segel Weight Loss: April 2012 vs. July 2013

Jason Segel is sure looking slimmer lately! And it's not just appearances: the 33-year-old funnyman spilled to E! that he's been getting into shape on purpose, for a film. A film where he gets naked.

This isn't his first time at the rodeo — Jason stripped down in Forgetting Sarah Marshall — but Jason points out that "different characters require different body types."

On his upcoming film Sex Tape, which stars him and Cameron Diaz as a married couple that have to track down a lost porn video, he says, "It is R-rated," clarifying, "and I'm not in shape for no reason." Ooh la la!

So how does he do it? The healthy way! "I've just been living healthy, exercising, eating right — no more midnight pizzas," he says.

"This time when I take my shirt off, I've made a promise to myself, it doesn't have to be funny."

Somehow, that goal is noble and bittersweet at the same time. We love Jason both before and after his weight loss! But we will admit that he does look pretty amazing in the above "after" photo, taken at a TCA party on July 29.

What do you think of Jason's slimmed-down look?


Credit: Celebified Photo: Jason Segel Authors New Children's Book Series "Nightmares!"