Longer legs make men more attractive to women because they are perceived to make fitter potential mates, researchers have found.
But they must not be too long, just a little longer than average, because being lanky offers males no advantage in dating, the study said.
The scientists from Cambridge University tested the attractiveness of different limb proportions by asking 341 American women to give computer-generated male figures marks out of seven.
Leg length was measured from the hip to the top of the ankle.
The findings showed that the men rated the most attractive had legs that were slightly longer than average.
The researchers said that longer legs suggested a good balance between greater size and "averageness" - which is associated with good health.
By contrast, legs that deviated significantly from average in either direction - short or long - were associated with poor health.
Very long legs were linked with "often indicated deleterious genetic conditions" and short ones were linked to diabetes, heart disease, high blood pressure and dementia.
Writing in the journal Royal Society Open Science, the researchers, led by Dr William Skylark, said: "LBRs [leg-body ratios] that are slightly above the mean are associated with high socioeconomic status, good nutrition and developmental stability, as well as biomechanical efficiency during locomotion.
"The observed preference for LBRs that are at or slightly above the population mean accords with the idea that these LBRs signal the fitness of the prospective mate."