Drew Barrymore would happily sit outside her lover's house in a car but not in a "psycho-irritant" way.

The actress is famous for her colourful love life, having been married twice and dated stars such as actor Justin Long and musician Fabrizio Moretti. She is now thrilled to be engaged to art consultant Will Kopelman and has explained why relationships are so important to her.

"I really love being in love. I am that girl who will sit outside your house in a car at night. And I mean that in a sort of good-committed way, not a psycho-irritant," she joked. "When I'm in love, I really commit myself to things, whether it's work or a person. So when I find that new work love, I'll stalk it."

Drew's new movie is called Big Miracle and is based on the true story of an attempt to save three whales who were stuck near the Arctic Circle in 1988.

The film was shot in Alaska because director Ken Kwapis wanted it to be as believable as possible. That meant three animatronic whales were commissioned, much to Drew's delight.

"I didn't want to be playing acting," she told USA Today. "I needed a whale."

Other aspects of the shoot were hard for Drew. She struggled with the cold and the dark days, as she is a "sunshine junkie".

The star began to realise things might be hard when she packed for the trip all she took with her was some boots and a Fisher-Price globe which had a light in it.

"I didn't have anything [else] to offer. I lived at the [outdoor store] REI once I got there. That was definitely helpful," she laughed.

The adverse weather had another effect on Drew. She developed a ravenous hunger because she wasn't used to being so cold, and would often go out for meals with her co-star John Krasinski and his wife Emily Blunt.

"I definitely did put on a layer of five to eight pounds of protective blubber. You just couldn't tell under all of those clothes," Drew said. "When I got home to Los Angeles, I was like, 'Wow, Alaska. I really brought it home with me.'"