Pictures of people posing with an A4-sized piece paper across their waists are circulating on social media, sparking a debate about beauty standards.

The so-called ‘A4 Waist Challenge’ has people checking to see if their waistline can be hidden behind the width of the paper: a span of approximately 8.3 inches, or 21 centimetres.

The ‘paper thin’ trend originates from China, where it was described as a ‘fitness challenge’ by the state newspaper People’s Daily.

Luciana Rosu-Sieza, the executive director of the Bulimia Anorexia Nervosa Association, told CTV Windsor the A4 fitness challenge is far from attainable.

“We see that continuously with a lot of these requirements – that people can’t actually meet them and that’s why they’ve become so dangerous.

“Eating disorders have the highest death rate of any type of mental disorder,” she adds. “So when you’re encouraging things like this, what are people actually doing to physically fit into that mold of 8.5 inches?”

Students at Catholic Central High School in Windsor, all of whom said they know someone suffering from anorexia or bulimia, told CTV that they are alarmed at the photographs.

Others around the world took to Twitter to express their sentiments.

Even the Chinese government joined in. The Ministry of Public Security posted on its social chat site, Weibo, that the distance between the mainland and the island of Taiwan, was "just the size of a piece of A4 paper."