A new social media trend has kicked off in China, with thousands of people uploading photographs of themselves showing off their bodies and undertaking the challenge.
The trending topic, which asks people to prove they have a good figure by “reaching your belly button from behind”, is said to be based on a US health study.
Those who fail the challenge supposedly have to lose weight.
Dr Charlie Seltzer, a weight loss specialist based in the USA, spoke to Cosmopolitan about the trend - and insisted it doesn’t do anything of the sort.
He explained: “If you can touch your belly button from behind your back, you could be in better shape than someone who can't — but you shouldn't have a false sense of security about your health.
“You might have a small waist and look healthy, but your blood work could show that you're just as unhealthy as someone who weighs 400 pounds.”
And, thankfully, he added that if we CAN’T touch our belly buttons from behind, we shouldn’t immediately go on a crash diet.
Apparently factors like short arms or poor shoulder flexibility could prevent healthy people from passing the test, so “if you can't do it, don't be completely freaked out.”
There is also the danger that the new trend could promote eating disorders.
Speaking with the BBC, Jolene Tan, Programmes and Communications Senior Manager at Aware, said: “Quirky poses and pictures can be fun but sometimes they also become expressions of competitiveness or insecurity.
“[It’s just] one more way of scrutinising women's bodies to see whether they are 'good enough'.
"We need to do more to promote acceptance of diversity in women's bodies."
If you aren’t sure whether or not you need to lose weight, your best bet is to go and visit your doctor, who can take a look at your blood work, BMI, and more.
It should be much more effective than trying to touch your belly button!