SNAKES ON A PLANE star Kenan Thompson has embarked on a strict diet - so he can parody presidential hopeful Barack Obama on the upcoming season of U.S. satirical show Saturday Night Live. The heavyweight SNL regular, who has poked fun at African American icons like Revd. Al Sharpton, Bill Cosby, Don King and Aretha Franklin on the show, knows he has to slim down to play Democrat Obama. Thompson says, "It's going to be a real political year and I'd hate for the show to have to seek somebody out to play Obama when they have me sitting there." The funnyman hopes to lose 60 pounds (27.2 kilograms) off his 260 pound (117.9 kilograms) frame so he can portray trim Obama.