Jack Black is to go on a diet in the New Year.

The 'Gulliver's Travels' actor has made a resolution to drop 50lbs and is planning a strict exercise and diet regime to achieve his goal.

Asked about his resolutions for 2011, Jack told 'Access Hollywood': "I'm gonna drop fitty. I'm gonna drop fitty pounds.

"How many quarter-pounders with cheeses is that? I'm gonna drop 200 quarter-pounder with cheeses. (sic)"

He jokingly added: "Push-ups, sit-ups, and a strict diet of . raisins. That's my plan."

Jack attended the 'Gulliver's Travels' premiere in Los Angeles on Saturday (18.12.10) but wasn't accompanied to the family movie screening with his sons Sammy, four, and two-year-old Thomas, because they don't know he is famous.

The actor - who is married to musician Tanya Haden - explained: "I didn't bring my babies because they don't know I'm famous yet. I'm trying to keep it well-hid. They're like, 'Whatever. Daddy's daddy.' They think I'm a salesman.

"I think I'll wait until later to bring Sammy, my four year old. He might freak out if he realises he's sharing me."

Though his sons don't know he is a celebrity, Jack admits they do ask questions when they see photographers waiting for them.

He said: "Well, we went to the park the other day and there were some creepy crawlers in the bushes with cameras. And Sammy said, 'It's OK to take pictures in the movies, but not in real life.' And I told him, 'You're right.' "