"The day I finished Twilight, I started bulking up," says the 17-year-old
Credit: Interview magazine

Talk about growing pains. In order to compete with Robert Pattinson in the upcoming Twilight sequel, New Moon, Taylor Lautner had to transform from a cute kid into a ripped god – er, werewolf.

“The day I finished Twilight, I came home and started bulking up,” Lautner, 17, tells Interview magazine about his getting fit to return as werewolf Jacob Black. “For New Moon, I m 30 pounds heavier than I was in Twilight.”

What’s the biggest challenge living with his ab-tastic new physique? “I grew out of a lot of my clothes,” he says. “I went from a men s small to a men s large.”

With New Moon mania in full swing, fans of the bestselling vampire saga haven’t pulled any punches. “They are very intense, but it s cool that they re so dedicated and so passionate,” he says, even though “sometimes it becomes a little overwhelming.”

Case in point: costar Robert Pattinson – who plays brooding vampire Edward Cullen – was recently mobbed by fans in New York City. “We ve met many different fans: the criers, who come around quite often; the hyperventilators who stop breathing and have to have a medic come,” Lautner says. “We ve definitely seen some passion.”