Fans are very concerned about Khloe Kardashian's "disturbing" Instagram selfie.

The youngest Kardashian sister, 32-year-old Khloe, has found herself on the receiving end of backlash after posting a mirror selfie on Instagram yesterday.

Posting the photo to her 58 million followers, the reality TV star sits on the floor in the photo, her waist markedly sucked in by a Christmas-themed waist trainer.

“Even filming I got to have my waist snatched!” the personality, who is currently dating NBA player Tristan Thompson, wrote. “Thank you @premadonna87 @waistgangsociety for getting me ready for this holiday season!”

A photo posted by Khloé (@khloekardashian) on Nov 14, 2016 at 12:55pm PST

While some were peeved at Khloe for not adhering to strict U.S. Federal Trade Commission’s guidelines (by not disclaiming the post is a paid advertorial), more were upset about something else entirely.

That is, the dangers of the celebrity’s waist training obsession.

“Those are so bad for your body!,” commented one concerned fan. “They squish your organs together. People did this back in the old days but would start at a young age before their organs got developed and in the right spot. You can cause damage.”

Many agreed, adding, “that can’t be healthy,” and, “can she breathe?”.

“All your doing is telling little girls that they have to be skinny to be beautiful and that’s a damn sin,[sic]” wrote another.

“Disturbing… You look really sick please go to a Doctor.”

A photo posted by Khloé (@khloekardashian) on Feb 11, 2016 at 8:55am PST

While not all followers agreed – some described Khloe’s taut tummy as “amazing” and, more curiously, “naturally beautiful” – widespread worry about the long term effects of waist trainers is valid.

Earlier this year, upon squeezing into one of the rigid garments, Mamamia co-founder Mia Freedman explained: “Oh my gosh, I need to explain to you how it feels, I just can’t breathe, it makes me not want to talk which is a terrible thing for me.

“Because everything is so compressed, I can only take really small breaths and I feel really dizzy because I feel like I’m not getting enough oxygen.”

In March, Christopher Ochner, Ph.D., weight loss and nutrition expert at Mount Sinai Hospital, told Marie Claire that wearing a waist trainer for prolonged periods of time could result in “crushed organs, compressed lungs, and fractured ribs”.

The effectiveness of wearing waist trainers to maneuver fat away from the torso is also highly disputed.

“You can’t reduce the collection of fat in any one particular area of your body. If you push your stomach in, all the fat will go right back to where it was no matter how long [you wear the corset] for”, Dr Ochner added.

Another product Khloe regularly spruiks on her feed is ‘diet’ laxative tea, which has also been harshly criticised by medical professionals.

Do you wear waist trainers? Let us know in the comments…