Ben Stiller Reveals Major Lifestyle Change (VIDEO)

Ben Stiller is looking quite fit these days, and perhaps it has something to do with his latest film "The Watch." In the film, Stiller plays a neighborhood watchman and tests his physical limits in several action sequences. When Conan O'Brien beamed over Stiller's running scenes -- who knew he could run? -- the actor revealed his fitness secret.

"I just try to run like Tom Cruise because I think he is the ultimate runner," said Stiller. "I can do it for like about 15 yards, and then I get out of gas."

The actor also told Conan that he recently gave up coffee and embraced a vegan lifestyle. Stiller doesn't like to call himself a vegan, however, and mentions the hardships he faced beginning his new dietary venture. "I had to tell my parents I was a vegan, I came out to them," said Stiller. "They were a little bit confused at first, but now they're supportive."

Being a vegan hasn't been an easy ride for Stiller, who admits he still misses certain foods. "I ate kale chips today," said Stiller. "I wanted to have ribs, but I had kale chips."

Watch the above video for more about Stiller's new lifestyle and his thoughts on nut cheese.