If you've not yet come across "waist training", then we can only deduce you've been living under a rock for the past couple of months (and maybe that's for the best).
Made popular by the likes of Kim, Khloe and Kourtney Kardashian, the fitness phenomenon involves using an elasticated shaping belt (similar in appearance to a corset) to constrict the waist.
The aim is to make the waist slimmer to create an emphasised hourglass physique.
But while it might sound too good to be true. Is it actually safe?
First things first, it's important to set the record straight: waist training is completely different to corset training.
Dr Galyna Selezneva, an aesthetic medical doctor practising at the Dr Rita Rakus clinic in London, explains to HuffPost UK Lifestyle: "Formal corset training takes year of dedication and is not a quick fix to achieve a small waist. People such as Dita Von Teese have spent years training their body and waist through proper use of corsets."
"The latex waist trainers that are culturally popular at the moment will not realistically create drastic changes to the body. So don’t believe the waist training gym selfies."
Premadonna, the woman behind Kim Kardashian's waist training obsession, claims that her 'Waistgangsociety Waistshaper' can reduce waist size by 3-4 inches.
"It also flattens the midsection and reduces excess belly fat," she says.
Slimming results vary depending on the individual: "There isn't any specific time frame. It could simply happen overnight or it could take up to three weeks."
But to see the full benefits, users are expected to wear it for a minimum of 3-4 hours a day.
Now to answer the question on everybody's lips: is crushing your midriff for long periods of time really safe?
While Premadonna says that there are "no dangerous side effects", there are many who beg to differ and personal trainer, Joshua Silverman, is one of them.
"The waist trainers made so popular by the likes of Kim Kardashian should be avoided at all costs, for more than one reason," he warns.
"Waist trainers work by constricting the abdominal walls, which is where important muscle and adipose tissue sits to protect your internal organs. When you constrict this area, it stops blood flow getting to this tissue, and therefore to those organs."
He continues: "Not only this, but when constricting, your body cannot release fat from that area. This means it actually could even start gathering fat there, due to the fact that it can't free up any fatty acids.
"So rather than reducing your waist size, you could actually do the opposite in the longer term."
Story continues below...
Dr Selezneva adds that waist training can also damage your ribs and bones.
"In order to achieve a tiny waist, the ribcage must be minimised which is achieved by reshaping the cartilage that connects the ribs to the breastbone."
"The upper seven pair of ribs are unaffected by waist training as their cartilage attaches directly to the sternum and cannot be reshaped," she reveals.
"However, the eighth, ninth and tenth pair of ribs, known as the ‘false ribs’ are not directly connected to the sternum and therefore can be reshaped through the waist training. Over many years, these ribs are slowly pushed closer together."
Waist training is particularly dangerous, explains Dr Selezneva, because there's a risk that young people will easily be influenced by what they see on social media.
"The pictures that these celebrities put up on Instagram endorsing the waist training will influence their followers into believing they can achieve their figures by doing the same, without highlighting the risks they present to their bodies," she says.
"With younger people, their bodies and muscles are still developing so any damage done is more likely to be permanent."
The secret to a slim and toned waist, without causing damage to your bone structure, lies in exercise and watching what you eat.
Silverman suggests that the best way to "whittle down the waist" is to follow a calorie-controlled diet (because it's no good exercising the area if you are eating more than you're burning off).
He also recommends resistance training, alongside rotational and static ab exercises: "Do moves like squats and lunges with heavy resistance. This burns more calories, giving you more bang for your buck."
"Combine this with rotational moves for the abs like the Russian Twist," he adds. "Alongside static ab exercises like the plank."
That certainly sounds like a plan.