I think Gabourey Sidibe did such an amazing job in “Precious”, it’s hard to fathom another actress portraying that difficult role. So it was surprising to me that Jennifer Hudson was initially cast to play Sidibe’s part:

Around the time when Hudson was wrapping up her run of appearances and award shows for Academy Award-winning “Dreamgirls,” she was asked to play the lead role by director Lee Daniels. But the thought of packing on the pounds (much like she did for “Dreamgirls”) was unattractive to the Oscar winner.

“I had done that with Effie… and as much as I was moved by this film,” she said. “I wanted to try a role that had nothing whatsoever to do with my weight.”

Shortly after, Hudson went on to co-star in the first “Sex and the City” movie and lose more than 80 pounds, while Sidibe shot into the spotlight with her breakout role. (Source)

You learn something new everyday, huh?