Natalie Portman stunned by factory farming facts in new film

Natalie Portman has been left stunned by alarming factory farming statistics used for her new documentary Eating Animals.

The vegan star narrates director Christopher Dillon Quinn's hard-hitting new film, which investigates where Americans get their meat and poultry from.

Animal-loving Natalie knew the documentary would be tough to watch, but she had no idea the film would throw up such shocking information.

"I finally learned why drugs are so essential to factory farming poultry - healthy birds don't require drugs; sick, mutated ones do," she says in the film.

"Turkeys have been so genetically altered that they're no longer capable of having sex; they're all artificially inseminated.

"I learned that because corporations want to pay less for feed and Americans like the taste of fat, today's meat birds have been bred with mutant obese genes to grow faster and fatter than ever imaginable before, so much faster and fatter that if a human baby had her growth similarly accelerated, a two month old would weigh more than 600 pounds."

The film, based on a memoir written by Portman's friend Jonathan Safran Foer, chronicles the history of factory farming in America, and features interviews with whistleblowers, who are keen to expose what the average American is putting in his or her body, and old school independent farmers, who are struggling to survive in an era where more and more food companies are turning to mass production and away from cage-free, traditional farming.

Portman, Safran Foer, and Quinn are also among the producers of the hard-hitting documentary, which will be released next month (Jun18).