In Hollywood, super heroines are super skinny, while super heros are not

In the new “Iron Man 3,” Gwyneth Paltrow’s Pepper Potts gets upgraded from mere Tony Stark love interest to doing some butt-kicking herself.

While donning an impressive set of Tracy Anderson-sculpted abs – which she flaunts in 3D at every opportunity – there’s no mistaking Paltrow’s ribs jutting out of her skinny frame.
Paltrow joins a long list of teeny tiny A-list beauties hand-picked to star in super hero films. Pin thin Anne Hathaway played Catwoman. Scarlett Johansson – who is considered a little more realistic in size by Hollywood standards but in real life is as petite as they come -- played Black Widow.

You get the picture.

So what's up with Hollywood’s insistence on using itty bitty gals to fight off much larger, muscled-up combatants?

Roberta Mancino, who did stunts for "Iron Man 3," says audiences simply want to see onscreen what they see in fashion magazines.

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"The female action stars of the past definitely had more curves," she told FOX411's Pop Tarts column. "Now every bit of fat has to be removed for the camera. The body types seen in films today would be a much better fit on a catwalk in Milan than fighting bad guys."

“Actors in Hollywood are hired for their star power. Whether or not they look the part is up to them and their commitment to look ‘believable.’ Sometimes the superhero movies have so many special effects and are considered eye candy,” said film producer and comic book expert Madison Jones. “I can’t think of one really believable female action star currently. It’s just America’s vision of beauty. The fanboys and fangirls online think (the body typing) is ridiculous – but average movie goers probably don’t care.”

Vulture Magazine raised the issue of the skinny super heroine in 2011 ahead of the release of “Colombiana,” in which Zoe Saldana took on the lead, Cataleya.

“Saldana resembles a supermodel who could be toppled not just by a gang of thugs but if a stuntman grabbed her the wrong way, and when she roundhouse kicks an assailant, Saldana looks like a spider doing a cartwheel,” the mag stated. “But right now, action heroes and heroines seem to be racing to comically opposite extremes.”

Of course, if a skinny male Hollywood star attempted a big action or hero role without pumping iron and packing on pounds in the preparation phase, he’d likely be the laughingstock. Hugh Jackman gained 40 pounds for the last installment of “Wolverine,” and told us he sought dietary help from former wrestler Dwayne “The Rock” Johnson. Chris Evans pumped up before stepping into his “Captain America” shoes, and even Robert Downey Jr. exhibits a ripped and powerful physique in “Iron Man 3."

"Absolutely there is a double standard and it is extremely unfair to women," noted casting director Holly Wolfe.

And while super skinny super heroines are are currently in vogue, it wasn’t always the way. Sigourney Weaver caused jaws to drop with her don’t-mess-with-me muscles in 1979’s “Alien,” and Lucy Lawless’s pack-a-punch biceps were applauded for its believability when “Xena: Warrior Princess” hit the television airwaves in 1995. Actress Jennifer Garner was all muscles and power with her athletic physique as she took on the leading lady in “Alias” in 2001 and as the Marvel superhero “Elektra” in 2005.

Famed director Stephen Soderbergh took quite the risk when he hired a then Hollywood no-name, but true life MME fighting champion Gina Carano to take the heroine helm in his 2012 action thriller “Haywire.”

“I do one thing really well and that is be physical,” she told us ahead of the movie’s theatrical release. “I’m absolutely ready for more movies, but I understand that that is not always easy, so I’ll stay positive and hope.”