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This is Scientific American's 60-Second Science. I'm Cynthia Graber. This will just take a minute.

Many people love what they consider a suntan's healthy glow. But the color you get from eating vegetables might be the most attractive glow of all. That's according to research in the journal Evolution and Human Behaviour.

Researchers controlled the diet and evaluated the skin color of 82 participants for eight weeks. Those who ate more fruits and vegetables had a yellower hue¹ to their skin. That tone comes from carotenoids in the fruit and veggies, which are linked to better immune defenses and reproductive health.

In related studies, the scientists recruited volunteers to look at photographs of 51 faces. They could manipulate the colors of the face to increase the darkness or the yellow tones. They were asked to adjust the colors until the faces looked to be what the subjects considered the most healthy. And the majority preferred a yellowish tone, like that produced by carotenoids. This held true for Caucasians in the U.K. and black Africans in South Africa.

The researchers say the preference could be a gauge² of vigor—many animals let their health be known to potential mates through vibrant³ coloration. So eat fruits and vegetables if you want your face to advertise your fitness.

Thanks for the minute. For Scientific American's 60-Second Science, I'm Cynthia Graber.