Taylor Lautner is opening up about bulking up for his role in the highly anticipated sequel to 'Twilight,' in which Taylor becomes a strong member of a wolf pack.

Taylor revealed just how much muscle he had to put on for 'New Moon' in Interview magazine, saying:

"As soon as I finished filming 'Twilight,' I knew I had to get to work right away; there could be no waiting involved. The day I finished 'Twilight,' I came home and started bulking up. For 'New Moon,' I'm 30 pounds heavier than I was in 'Twilight.'"

Taylor tells the mag that his new physique changed his size from a men's size small to a men's size large.

The 17-year-old star tells Interview the efforts it took to make the stunning transformation:

"I was in the gym five days a week, two hours a day. At one point, I was going seven days straight. I had put on a lot of weight, and then I started losing it drastically, so I was worried. It turned out I was overworking myself. My trainer told me that I couldn't break a sweat, because I was burning more calories than I was putting on. The hardest thing for me was the eating. At one point I had to shove as much food in my body as possible to pack on calories. My trainer wanted me to do six meals a day and not go two hours without eating. If I would cheat on eating one day, I could tell -- I'd drop a few pounds."

Taylor, who plays Jacob in the vampire flick, also tells the mag that the he is "close" friends to co-stars Robert Pattinson and Kristen Stewart.

'The Twilight Saga: New Moon' hits theaters November 20.

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