Taylor Lautner has a buff, sexy body — but he hates it!

Due to major physical changes that occur in the character of Jacob Black throughout the Twilight series, the director of Twilight’s sequel, New Moon, considered replacing Lautner with a different actor.

In a desperate bid to keep the role, the 17-year-old hit the gym, and gained approximately 30 pounds of muscle.

But, according to the National Enquirer, the young star is desperate for the smash hit film franchise to end so he keen stop pumping iron and look himself again.

“Normally Taylor is much thinner,” an insider told the tabloid. “It’s a struggle to keep the weight on because he likes to run. He’s into martial arts and has a pretty quick metabolism.

“He says he doesn’t feel like himself. He intends to stay fit, but he says he will take off at least 20 pounds once filming wraps on the final installment of Twilight.”

New Moon — which also stars Robert Pattinson and Kristen Stewart — hits movie theaters on November 20, 2009.

Meanwhile, Lautner was seen lunching with a mystery (and older) girl outside at Hollywood’s Sunset Marquis Hotel Saturday.