Hilary Duff trades in the workout gear for a sexy little black dress on a trip to the cinema

By Daily Mail Reporter

PUBLISHED: 04:35 EST, 26 September 2012 | UPDATED: 06:38 EST, 26 September 2012

When in doubt, put on a little black dress, Hilary Duff must have thought.

The actress showed off her slim post-baby figure in a sexy evening dress teamed with a sparkly silver clutch and heels, as she visited the cinema in Hollywood with a friend on Tuesday.

It might be a little overdressed for a trip to the movies, but the new mother of Luca looked radiating in it nonetheless.

Movie time: Hilary left baby Luca at home as she enjoyed some girly time with her friend

Movie time: Hilary left baby Luca at home as she enjoyed some girly time with her friend

It's a far cry from the fluorescent green leggings the 24-year-old was seen wearing earlier in the day.

The Gossip Girl actress has been hitting the gym hard lately in an effort to lose the baby weight, after son Luca was born in March of this year.

And it seems to have paid off. The star has been sporting a slimmer figure lately, although the criticism of her post-baby body has affected her.

Stepping out: The actress pulled out her LBD for a trip to the cinema

LBD: The actress kept her make-up minimal and lets the dress do the talking

LBD: The actress kept her make-up minimal and lets the dress do the talking

'Obviously, I'm not whe! re I want to be... but I'm working hard and I'm doing everything I can to lose the weight the right way,' Hilary said.

'I'm breast-feeding, so you have to be careful and not do anything too drastic.'

The young mother clearly dotes on her baby son though, as she's been enthusiastically tweeting pictures and news to her fans to keep them updated.

Last week, Hilary posted a picture of her adorable tot getting his first tooth.

'HELLO FRIENDS!!!!! Check out me teeth!!,' she tweeted, accompanied by a picture of the little boy sporting a big grin.

Gym time: The actress was spotting going for a workout earlier that day in bright green leggings

Gym time: The actress was spotting going for a workout earlier that day in bright green leggings

Gym time: The actress was spotting going for a workout earlier that day in bright green leggings