START EATING, GIRLS!

Catherine Zeta-Jones, Renee Zellweger and R&B singer Mya nearly gagged on their fat-free yogurt when the director of their upcoming flick “Chicago” ordered them to GAIN 10 pounds! The movie’s set in the 1920s when gals were more voluptuous, he explained — so start eating. “It’s usually the other way around!” gushed Mya.