Gentlemen prefer big bottoms: How slim Michelle Williams used padded pants to get Marilyn Monroe's hourglass figure
Williams used padded underwear for fuller shape'Occasionally we added something to her butt', says producer Harvey Weinstein

Marilyn Monroe epitomised the hourglass silhouette, with her nipped-in waist and ample bosom and bottom to boot.

So size zero actress Michelle Williams must have found it a daunting prospect as she geared up to play the 1950s sex siren for the recent biopic.

For months the 31-year-old stepped up her diet, saying 'I wasn't watching what I ate' but to ensure she had the perfect derriere Williams purchased some secret underpants.

Michelle Williams

Michelle Williams

Before and after: Michelle Williams wore Huit’s Magic Pulp pants to achieve Marilyn Monroe iconic hourglass figure for the recent biopic

Featuring cushion pads, which sit over the bottom to give it a fuller shape, the Hollywood star's wardrobe team visited Rigby & Peller to snap up a pair of Huit’s Magic Pulp pants.

Priced at 42.00 the underwear, which is manufactured in France, has been a hit following publicity around Pippa Middleton and Jennifer Lopez.

According to reports, Pippa’s appearance at the royal wedding, caused sales of ‘padded pants’ to rocket as women try to emulate her shapely derriere.

Huit's Magic Pulp pants feature pads, which help give the bottom a fuller shape

Huit's Magic Pulp pants feature pads, which help give the bottom a fuller shape

And last year the fuller figure was back in vogue finally overtaking the 'waif' look which has dominated catwalks and magazines for decades.

Scarlett Johansson, Nigella Lawson and
hit TV series Mad Men were all credited with fuelling the trend as sales
of 'shapewear' more than trebled.

And thanks to Williams's lingerie choice, she flaunted Marilyn's enviable figure without a hitch.

Nigel Addison UK Sales Director of lingerie brand Huit said: 'Marilyn
had incredibly legendary and eye-catching curves and the Huit Magic
Pulp pants have helped Michelle to re-create Marilyn’s bottom

Voluptuous: Marilyn Monroe epitomised the hourglass silhouette

Voluptuous: Marilyn Monroe epitomised the hourglass silhouette

'Michelle’s boosted bottom can clearly be seen when you compare before and during filming.'

Harvey Weinstein, producer of My Week With Marilyn also applauded the transformation.

He told the Huffington Post: 'She actually didn't gain the weight.

'Occasionally we added something to her butt, but that was about it.

'She's got a great figure and up on top, or whatever, she's in a good place.'

The film documents the tense interaction
between legendary actor Sir Laurence Olivier and Marilyn Monroe during
production of 1957 movie The Prince and the Showgirl.

As well as wearing body padding, Williams also had to bleach her hair every few days to get the platinum blonde look – and spent three hours a day in make-up.

My Week with Marilyn is out at selected UK cinemas now and available on DVD from March 2012.