The film role that will put Mariah Carey back on the big screen originally belonged to Janet Jackson. Jackson has revealed she gained almost half her body weight to play a Southern waitress in "Tennessee" and weighed in at 180 pounds but had to pass on the project when filming schedules started to interfere with her pop comeback.

The singer confesses she was preparing for the unflattering role when she was snapped looking overweight and sluggish in tabloid photos at the end of 2005, but she was sworn to secrecy about the film. Jackson, who recently turned 40, has since shed the extra weight thanks to a hardcore fitness regime.

She says, "I put on the pounds for a film I was to do with Lee Daniels, the producer of Monster's Ball, which a lot of people didn't know. They (producers) wanted a full-figured woman. She's from the South, a waitress ... They wanted to see me in a different light, as a heavier woman. I was excited about it. (I ate) whatever I desired: 'Ooh, that looks good, give me that piece of cake!' That was the fun part. They had to push the film back. The timing didn't quite work with trying to finish my album, and unfortunately I wasn't able to do the film."

Carey has since taken over the role.

Check out some Janet Jackson photos HERE.

(This news article provided by World Entertainment News Network)