IESB has a new interview with Taylor. He talks New Moon. Here's part of the interview:
Q: Did it ever feel like you were really in danger of not getting the role in this movie?
Taylor: Honestly, I knew where my character went in New Moon and that’s all I tried to stay focused on. I couldn’t control things outside. I couldn’t control the media. But, I could control what I was doing to portray Jacob Black correctly. That’s what I stayed focused on, the whole entire time.
Q: Did that start with going to the gym and gaining 30 lbs?
Taylor: Absolutely. Jacob transforms a lot in New Moon, not only physically. but mentally and emotionally as well. So, it was a matter of getting to the gym and eating the right food, and a lot of it. But, it was also about reading and studying the book and the character, over and over and over again, so I could have his character down as well because he changes in many, many different ways
Q: How does he change?
Taylor: Basically, my job was to continue what I started in Twilight, which was this extremely happy, friendly, outgoing guy, who is best friends with Bella. I had to continue that for the first half of the film, but as soon as he transforms, he snaps and becomes a completely different person. He’s dealing with his issues and it’s really hard for him