Keira, Sienna and a curry on film

When Renee Zellwegger had to pile on the pounds to fill her Bridget Jones granny pants, she told of struggling to consume a calorie-rich diet every day.

But I hear whippet-thin Keira Knightley, who has been told to fatten up for her role in her new movie The Edge Of Love, is enjoying every one of her four daily meals on location in west Wales.

Keira, seen right with her co-star Sienna Miller, has been munching her way through huge amounts of food to make sure she keeps her weight up.

"Both Keira and Sienna have bigger appetites than many of the men on set," says my Welsh spy.

"Keira was told to beef up for the role and she and Sienna have both been having food competitions to see who can eat the most.

"At the moment they are on a curry diet where they have curries for lunch and dinner, and eggs Benedict for breakfast."

It's a hard life.

The girls are said to be enjoying hearty meals while filming

Sienna and Keira have become close friends since working together on this film