Cameron Diaz to play fitness instructor?

Actress Cameron Diaz is reportedly in talks to play a fitness instructor in new movie What to Expect When You're Expecting.

Diaz may play the role of a weight-loss instructor who hosts a fitness TV show in the romantic comedy based on the bestselling guidebook for new parents by Heidi Murkhoff, reports Contactmusic.com.

The original screenplay by Heather Hach was set to feature seven sets of expectant parents but has now been cut down to five.

Mike Medavoy, Arnie Messer and David Thwaites will produce the movie for Lionsgate while  Kirk Jones will direct it.