Meryl Streep and Amy Adams piled on the pounds while shooting 'Julie and Julia'.

The 'Doubt' co-stars reunited for the forthcoming film - which is about world-famous chef Julia Child and writer Julie Powell, who challenged herself to cook Julia's recipes - and admit the amount of food they had to eat for their roles wasn't good for their waistlines.

Meryl said: "I gained 15 pounds - I'm still trying to lose it! It was worth it."

Amy added: "I ate a lot! Cooking is like love - it should be approached with abandon."

The actresses were unable to escape gaining weight as they were ordered to enjoy the food featured in the scenes by director Nora Ephron.

Nora revealed: "That's one of the things I said in rehearsal. Everyone has to eat in the scenes, and everyone really went for it."