Celebrity Hot or Not: Gwyneth Paltrow stuns in dress and no underwear

Iron Man 3 star Gwyneth Paltrow stuns in dress with entirely sheer side panels (and no underwear) at film premiere

She was named the World’s Most Beautiful Woman in People magazine on Wednesday.

And on the same day Gwyneth Paltrow showed just why as she put on a sophisticated appearance at the Marvel’s Iron Man 3 Hollywood premiere.

The 40-year-old arrived on the red carpet at the El Capitan Theatre in Los Angeles, California in a gown which looked demure from a distance.

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World's Most Beautiful: Gwyneth Paltrow arrives at the premiere of Walt Disney Pictures' Iron Man 3 at the El Capitan Theatre on Wednesday in Hollywood, California

Fearless and fun: Gwyneth's bottom was visible in the sexy number

Plenty to see: The blonde's hair was tossed over one shoulder to show off the back of her gown too

However on closer look the actress’ Antonio Berardi dress featured mesh panels down the sides, showing off her hips and décolletage area.

The material would have made it almost impossible for her to wear underwear beneath the number.

While she could have quite possibly been wearing a strapless bra, briefs would have been too tricky.

Great mood: The blonde glowed with her minimal make-up look on the red carpet

Optical illusion: Her dress featured a white silhouette and a mesh sheer panels on the side

Deceptively demure: The actress' ensemble didn't allow much room to wear underwear

Cool co-stars: Actors Sir Ben Kingsley, Gwyneth and Robert Downey Jr. posed for a group snap

The look of her item of clothing – which created the optical illusion of a curvy white silhouette down the middle – also drew attention to her tiny waist.

With a dark green peplum section that matched her kimono style arm cuffs, the slender thespian - who plays Pepper Potts - looked in great shape.

She is known for taking up often strict healthy eating plans - such as eating only macrobiotic meals at one point - in an effort to stay trim.

Perfect from every angle: Gwyneth smiled widely as strutted along the red carpet

Dressed to impress: It's not hard to see why Gwyneth was recently crowned Most Beautiful Woman by People magazine

Dressed to impress: It's not hard to see why Gwyneth was recently crowned Most Beautiful Woman by People magazine

They love her! Gwyneth waved to her adoring fans as they screamed her name

Enthusiastic talker: The screen star was happy to engage in interviews with waiting press

Snap happy: Actors Ben Kingsley and Gwyneth cosied up for a photo

Happy to see her: Robert Downey Jr. grabbed Gwyneth's body close to his and gave her a smooch

She allowed her skin to glow in natural make-up and wore her blonde locks straight and to one side over her shoulder.

It’s no wonder the mother of two children with Coldplay singer Chris Martin - who was nowhere to be seen on the night - was given the prestigious beauty accolade.

She added a fun twist to her appearance with purple nail polish and paired a large drop earring with a contrasting small stud that evening.

Purple pat: Gwyneth put her manicured fingers on Robert Downey Jr's shoulders as he waved to onlookers

Pretty in poppies: Actress Bella Thorne wore a floral two-piece set while Debby Ryan donned flowers on her monochrome dress

Date night: Chris Hemsworth attended the event with his wife Elsa Pataky

The kids love it: Tracy Anderson arrived with her children to the early showing

Disney star Bella Thorne was also going for a style which emphasised her stomach area.

The 15-year-old wore a poppy print ensemble which featured a cropped top to display her toned tummy.

She paired the peplum skirt with a pair of peep toe black heels and wore her red lucks up in a bun on top of her head, accessorising with a stand-out necklace and wearing red lipstick with yellow nail polish.

Beauties in black: Olivia Holt and Hayley Atwell wore ebony dresses

Flower power: Actress Kat Dennings wore a floral frock to the event

Ray of sunshine: Actress Jaimie Alexander revealed her slim figure in a yellow dress and Chelsea Kane also wore the hue

The Shake It Up! actress wasn’t the only Disney favourite to grace the screening.

Suite Life On Deck star Debby Ryan, 19, was also in attendance after tweeting, ‘Pulling my hair up at @SalonBenjamin. Stoked to see Iron Man tonight, & to show you my carpet look.’

The red head wore her locks up and donned a bandeau item which had a leather top and white floral skirt.

Light frocks: Laura Morano and Emily VanCamp wore cream

Showing skin: Cobie Smulders wore a scarlet dress with a low V-neck cut and Rebecca Hall donned a black sheer number

Actress Jaimie Alexander, 29, flaunted her thin frame in a yellow dress with a row of flowers above the bust to match her ring.

The raven-haired beauty was complain on Twitter earlier about her thin body and revealed she was working to bulk up.

She wrote: ‘For the first time in my life...I'm having difficulty adding weight/muscle to my body. I actually HATE my thin frame at the moment....SO....

Sun shades: Robert Downey Jr. and Susan Downey wore dark glasses on their eyes

She bangs! The man who plays Tony Stark showed off his spouse who stood out in a bright orange frock

Clowning around! The star was paid $50m to appear in the blockbuster

The baddie: Actor Sir Ben Kingsley - who plays The Mandarin - with wife Daniela Lavender

‘Ladies, STRONG is the new skinny. I'm working with my trainer @sarathek with @iheartfitnessxo to add healthy weight + muscle.’

The thespian later added: ‘I will post pics in the coming weeks/ months and give tips on how to add healthy muscle and maximize strength. Are you with me?! #TeamWork.

‘My girls, let's encourage and motivate each other! Join me in getting STRONG and FIT :) EveryBODY is different. Be the best YOU can be!’

Film stars: Actor Ashley Hamilton star as Jack Taggert and Jon Favreau is Happy Hogan

Big boss: Director Shane Black posed in a black T-shirt and beige blazer

Marvel's stars: Writer/director Joss Whedon and Ty Simpkins plays Harley

The film’s main star Robert Downey Jr. attended with his wife Susan and they both donned dark sunglasses.

He wore a smart pinstriped suit while she stood out in an orange frock which had material gathered at one side.

Twilight Saga actor Peter Facinelli, 39, was also suited and booted at the Walt Disney Pictures event.

Coupled up: Guy Pearce and wife Kate Mestitz posed for pictures

Suited and booted: Twilight actor Peter Facinelli wore navy blue with beige

Suited and booted: Peter Facinelli and Don Cheadle who plays James Rhodes / War Machine

Big screening: Writer Stan Lee apparently plays Stan The Man in the flick

Family film: Andy Garcia brought his young boys along to the screening

Writer/director of The Avengers 2, Joss Whedon, and Iron Man 3 director Shane Black were also photographer arriving.

Jon Favreau (Happy Hogan), Ty Simpkins (Harley), writer Stan Lee (Stan The Man) and Ashley Hamilton (Jack Taggert) additionally posed upon entry to the gathering.

The film is released in the United Kingdom on April 25 and the synopsis reads that when Tony Stark's world is torn apart by a formidable terrorist called the Mandarin, he starts an odyssey of rebuilding and retribution.