Science has confirmed what women have known for years - men really do look at women's bodies more than their faces.

But a study published in the journal Sex Roles shows that women are just as guilty of staring at other women's bodies more than their faces.

The US study took 29 women and 36 men who were fitted an eye-tracking system which measures how many milliseconds the eyes remain on a certain spot.

Photographs of 10 women were shown, each with three digitally altered body shapes - curvaceous, much less curvaceous and in-between.

Both men and women focused on women's chests and waists.

Those women with bigger breasts, narrower waists and bigger hips prompted longer looks.

Lead author of the study, Dr Sarah Gervais of the University of Nebraska-Lincoln, said the explanation may be evolutionary as men are said to be drawn to more shapely women for childbearing, while women may be checking out their competition.

"We live in a culture in which we constantly see women objectified in interactions on television and in the media. When you turn your own lens on everyday, ordinary women, we focus on those parts, too," she told USA Today.

"Until now, we didn't have evidence people were actually doing that to women's bodies," she said. "We have women's self-reports, but this is some of the first work to document that people actually engage in this."

The eye tracking system is said to be more useful then questionnaires or interviews, which are subjective, because people may not known how much the subconsciously check out women's bodies.