From left, Mariah Carey, director Lee Daniels, Mo'Nique and Paula Patton at the Sundance Film Festival premiere of award-winning Push: Based on the Novel by Sapphire. (Matt Sayles/Associated Press)

A dark film about an overweight, pregnant teenage girl abused by her parents prevailed at the Sundance Film Festival with three trophies, including best picture and the audience award for top film.

Push: Based on the Novel by Sapphire also earned a special jury prize for acting for comedian Mo'Nique, who portrayed the girl's mother.

'This is speaking for every minority that's in Harlem, that's in Detroit, that's in Watts, that's being abused, that can't read, that's obese and that we turn our back on'—Push director Lee Daniels

"This movie made us laugh, made us cry and basically blew our minds," writer/director Mike White, a member of the five-person jury that picked the movie, told the audience at the awards ceremony on Saturday night in Park City.

"This is so important to me because this is speaking for every minority that's in Harlem, that's in Detroit, that's in Watts, that's being abused, that can't read, that's obese and that we turn our back on," said the film's director, Lee Daniels, as he picked up the audience award.

"And this is for every gay little boy and girl that's being tortured. If I can do this ... y'all can do this."

Based on the 1996 first novel by the poet Sapphire, the film also stars Mariah Carey and Paula Patton alongside newcomer Gabourey Sidibe, who portrays pregnant 16-year-old Precious Jones.

Meanwhile, Sin Nombre — a look at illegal Mexican migrants — took home the best director prize for Cary Joji Fukunaga and best cinematography for Adriano Goldman.

The other big winner — in the foreign film division — was Five Minutes of Heaven. The drama about two men on opposite sides of Northern Ireland's conflict earned Oliver Hirschbiegel and Guy Hibbert, awards for best director and writer, respectively.

2nd time for documentary director

The 11-day festival, a showcase for independent film, also handed out a documentary prize to We Live in Public. The Ondi Timoner film profiles little-known internet pioneer Josh Harris, and his failed "lifecasting" art projects in 1999 and 2000.

It marked a second Sundance accolade for Timoner, whose Dig! won the same award in 2004.

Timoner dedicated the honour to Harris, calling him "the first subject I've ever had that said I don't care how you portray me as long as you make a great film."

Best directing in a documentary went to Natalia Almada for El General, an examination of 100 years of Mexican history.

Michael Cera film gets screenwriting honour

Nicholas Jasenovec and Charlyne Yi won the Waldo Salt screenwriting award for Paper Heart, a hybrid documentary-improv road movie featuring Yi and Canadian actor Michael Cera of SuperBad.

"I feel sick. I'm sweaty. I smell bad," said Yi, a performance artist and comedian who is also Cera's girlfriend.

Other winners included:

• Best international drama: The Maid (La Nana).
• Best international drama, audience award: An Education.
• Best world documentary: Rough Aunties.
• Best world documentary, audience award: Afghan Star.
• Best director, world documentary: Havana Marking for Afghan Star.