We tend to assume that health and beauty go hand-in-hand. But a new study suggests that the female body types we see as "healthy" are very different from those we see as "attractive," revealing a dangerous disconnect.For the study , recently published online in PLoS One, researchers wanted to go beyond the BMI and figure out the composition of fat and muscle that we find most attractive in men and women. To do so, they took pictures and body composition measurements of 192 people to create 30 composite images.Then, they had 63 other participants manipulate the images with a computer program, instructing them to either make the photo look as "healthy" or "attractive" as possible by changing the apparent amount of fat and muscle on the bodies. They weren't given any parameters or measurements about what constitutes "healthy."Results showed that, for photos of men, participants selected about the same muscle and fat percentages for both "healthy" and "attractive" categories. But for women, participants selected significantly lower body fat percentages for the "attractive" category than the "healthy" one. Perhaps most distressing was that participants selected ideal fat percentages that were actually slightly below the real healthy cutoff.Furthermore, the same amount of muscle was considered healthy and attractive for women's bodies, but only extremely low fat percentage was considered attractive. This suggests that the differences in what we view as "attractive" for women's bodies is driven primarily by fat rather than muscle mass.This is an especially dangerous combination because it shows exactly why so many of us feel pressured to forgo our health in pursuit of attractiveness. It also suggests yet another mechanism by which our society makes those who are perfectly healthy feel as if that's somehow not enough.This study looked at a very small and narrow sample (undergraduate students in Australia), so it's hard to say exactly how much these results reflect preferences elsewhere. Still, they suggest we have a long way to go towards accepting healthy — in all its many forms — as sexy.