Renee Zellweger has gained 4.5kgs in a bid to find a new man.

The 39-year-old actress - who is divorced from singer Kenny Chesney - has gone from a tiny UK size six to a slender size eight.

A source said: "Renee was worried her slim frame made her look gaunt, sickly and, worst of all, old. She is going to be 40 in six months and doesn't want to be single then."

Renee - who famously gained weight to play British journalist Bridget Jones in 2001 movie ‘Bridget Jones's Diary' and 2004 sequel ‘Bridget Jones: The Edge of Reason' - has reportedly completely changed her diet to maintain her new curvy figure.

The source added to a US magazine: "Renee used to eat only fresh fruit for breakfast, but now she allows herself the odd doughnut or bagel with cream cheese. And instead of working out five or six times a week, Renee isn't freaking out if she misses a session.

"She was so focused on maintaining a killer body that she was neglecting other aspects of her life. Let's hope her curves bring her happiness."

[View our Renee Zellweger pics]