New trend among girls in China: Proving their waist is smaller than a piece of paper

A scary new trend is making its way among women in China: The A4 challenge.

The name stems from a standard size piece of paper: 8.5 x 11 inches is, technically, size A4.

The idea is to prove that the 8.5-inch-wide paper will completely cover your waist.

Critics have slammed the bizarre trend for pressuring women strive for an unrealistic, unhealthy goal.

Though the A4 Challenge is primarily a phenomenon on Weibo - China's answer to Twitter - it's also caught on in the Instagram world.