A NEW 'fitness' trend encourages women to compare their waist size to a sheet of A4 paper (210*297mm).
The Chinese craze involves holding up the paper, which has a width of just 21cm, against the body.
Hundreds of thousands of social media users have taken to China's version of Twitter, Sina Weibo, to share their snaps.
The Chinese internet users have claimed that the slim waist fad is a healthy and attainable aim.
One Weibo user boasted: "I'm a size smaller than A4. I'm A5."
Critics have slammed the bizarre trend for pressurising women to try to reach an unachievable goal.
An angry Twitter user said: "So are they insinuating smaller is better? Not cool to offend the girls who don't measure up in this matter."
Another commenter remarked: "A4 paper waist challenge? Total rubbish", before joking that they wanted to turn the sheet of paper sideways.