Like so many social media fitness crazes, the A4 waist challenge ignores the notion that what is healthy for one person is not for someone of a different height or shape, and blindly demands the same results from all its participants, regardless of whether that is healthy for them or not.
The fad, which is currently taking China by storm, encourages young girls to compare their waists to an A4 piece of paper, with the aim to be equal to or thinner than the 21cm width of paper.
The challenge is aimed at young women and girls, and asks them to upload photos to China's version of Twitter, Weibo.
As Weibo users flood the social media platform with photos of their stomachs hidden by a sheet of paper, along with diet tips and photos of Chinese models, critics have slammed the craze for promoting unhealthy and unattainable standards.
"So are they insinuating smaller is better? Not cool to offend the girls who don’t measure up in this manner," wrote Twitter user John Disereits.
Others have chosen to address the craze as a joke.
This is not the first time China has faced criticism over a challenge encouraging women to be incredibly thin.
Last year, China's "Belly Button Challenge" went viral, which encouraged people to upload photos of themselves reaching behind their back and around their waist to touch their belly button.
But the Chinese Internet users partaking in the challenge say that the A4 challenge is a healthy and attainable goal.
“I’m a size smaller than A4. I’m A5," said one Weibo user.
Like all viral fads, the A4 waist challenge will pass, and hopefully in it's place will be a fad less dangerous and more embracing of healthy lifestyles and different body types.