Trying to be thinner than a piece of A4 paper has to be the most worrying new craze

The latest in a seemingly endless series of bizarre Chinese beauty fads on social media is also surely the most dangerous yet.

Young women and girls are posting photos of themselves holding up sheets of A4 paper to their waists in order to live up to an unrealistic standard of skinniness.

All across Weibo and Instagram, young women are trying to prove their body image credentials by completing the "challenge" under the hashtag #A4waist - and this is one "health" fad that spells danger.

One user wrote:

Guess I deserve another scoop of ice cream after all.

A standard sheet of A4 paper measures just 8.27 inches wide and 11.69 inches long.

A US size triple zero, or UK size 0, is a waist measurement of around 23 inches in circumference though the width of a waist might vary.

A succession of worrying fads have come out of China in recent times, including a trend for women to stare at the sun to 'help them lose weight'.

However, there has been some backlash to the trend, with many people criticising the fad and mocking it with pictures of their own.

On Instagram, colourme_ashy held a piece of paper over his stomach simply reading: "Too much pressure".

More: This woman silenced body-shaming trolls - in four amazing photos