The latest, and perhaps most disturbing body image fad of recent years, is undoubtedly the 'thigh gap' craze - a potentially eating-disorder level of skinniness few of us can reach healthily.
Blogs have sprung up advocating thigh gap weight loss plans, posting images of skeletal girls whose thighs don't touch. Alexa Chung's image has been repeatedly tumblr'd for thinspiration and Cara Delevingne's thigh gap even has its own Twitter feed (fan-created but reportedly followed by the model herself).
Like all diet fads there has been a fanfare of disapproval and concern in the media, but is that really going to stop girls and women feeling the pressure to conform to (often airbrushed) celebrity body shapes?
There is a even Wiki that explains how to get the thigh gap, though we should add that it contradicts other online diet and exercise programmes designed for the same end.
But this is hardly surprising. Having a gap between your thighs has pretty much nothing to do with exercise and even your diet. It's all down to your natural body shape.
For some of us, having a gap between our thighs is normal, natural and nothing to make a fuss of. For others, it's impossible to achieve without dipping into the murky waters of eating disorders and dangerous crash dieting. And if your body's not built that way, even that may not give you the longed-for gap.
Personal trainer Hayley Newton is baffled by the craze.
"This latest obsession is ridiculous because a person's ability to achieve a thigh gap solely depends on how wide their hips are," she explains.
"It all depends on the body type. For some, yes it is a sign of being too underweight. However it can just be a result of your body - you might have wide hips or even be slightly bow-legged, which gives you that look.
"And for that reason, the thigh gap is totally not a goal to strive for."
So shut down those 'thinspo blogs' and take down any celeb pics you've got stuck to the fridge and pay attention to yourself instead.
Hayley advises: "Concentrate on your own body, not someone else. Everyone's body is different, what works for one may not work for another. Focus on what you have been given and work for your body type."
Follow Hayley on Twitter.