AceShowbiz - Comedian Jack Black has set himself a hefty goal for 2011 - he wants to shed 50 pounds (22.68 kilograms) of his body weight. "The School of Rock" actor wants to embark on the New Year leaner and fitter than ever before and he's ready to begin a vigorous exercise and diet regime to slim down.

The rounded actor tells U.S. news show Access Hollywood, "I'm gonna drop 50 pounds. Push-ups, sit-ups, and a strict diet of... raisins! That's my plan."

In another news, Jack Black reveals he refuses to turn his film premieres into family affairs, because his two young sons have no idea they have a famous father. He admits he's yet to tell four-year-old Sammy and Thomas, two, exactly what he does for a living - and he's keen to keep it that way.

Speaking at the Los Angeles premiere of his new movie "Gulliver's Travels", he tells Access Hollywood, "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."

Black isn't the only celebrity parent keeping his star status under wraps from his little ones - the comedian's "Shallow Hal" co-star Gwyneth Paltrow recently admitted she had been hiding her profession from her two children, until her six-year-old daughter Apple found out she was famous from her classmates.