That was over 20 years ago in 2001.
Today he is 51, and has starred in 85 movies in total, 57 since Shallow Hal was released.
In Shallow Hal, I think Jack Black looks:
Shallow Hal scores 5.8 out of 10 on The Movie Database.
Jack Black's first acting role was as 'Roger Davis' in Bob Roberts, released in 1992 when he was 23.