By: Nancy J. White Living Reporter, Published on Fri Jan 14 2011

You don’t need an expensive Caribbean holiday this winter to look attractive and healthy. Just chow down on more carrots, sweet potatoes and mangoes.

You look like what you eat, according to a study in the journal Evolution and Human Behavior.

Participants manipulated the colours of 51 faces on a computer screen to make them look healthier. Consistently, they picked skin tones calibrated to reflect the intake of carotenoids, compounds found in fruits and vegetables, rather than tones simulating suntans.

“We were very surprised and pleased that people preferred the appearance from fruits and vegetables compared to suntans,” says David Perrett, a research professor at Scotland’s University of St. Andrews and an author of the study. “It’s doubly healthy to stay out of the damaging effect of the sun and eat more fruits and vegetables.”

Carotenoids are important in reproduction and immune responses.

In another part of the study, researchers surveyed students about their dietary habits and measured skin colour.

They found that just one or two more portions of fruits and vegetables a day resulted in a subtle shift toward the more healthy yellowish tone of carotenoid consumption.

Researchers found similar results when 10 participants took a 15 mg daily supplement of beta carotene for eight weeks.

Perrett stresses that the benefit comes not from one particular food but from consuming a variety of fruits and vegetables, which contain different types of carotenoids. The more colourful your diet — sweet potatoes, spinach, plums — the more colourful you’ll be.

You can eat too much of a good thing. Excessive consumption of carrots can produce carotenemia, a too yellowed skin tone that looks jaundiced.

Another experiment in the study looked at cross-cultural perceptions of skin colour.

At the University of Pretoria, black South Africans were asked to manipulate skin colour to make black South African facial images as healthy as possible. The results also showed a preference for increased carotenoid colouration.

Study co-author Ian Stephen, professor of psychology at the University of Nottingham’s Malaysia campus, points out in a press release that evolution would favour individuals who mate with healthier individuals over unhealthy ones.

Other species show similar effects, says Perrett.

“The bright yellow beaks and feathers of many birds can be thought of as adverts showing how healthy a male bird is,” explains the research professor.

“This study shows a similar effect in humans.”

Perrett, the head of St. Andrews’ Perception Lab, is researching whether people will change their food habits if shown an image of how their face would look on a healthier diet.

At the lab’s website, The Perception Lab, visitors can watch demonstrations and participate in experiments on judging skin quality and rating attractive faces.