Married At First Sight's Bec Zacharia faces backlash from fans and fellow MAFS stars as she undergoes controversial 'Barbie waist' surgery in Bali that's not available in Australia

Bec Zacharia is reshaping her ribs as she undergoes a controversial form of plastic surgery in Bali. 

The Married At First Sight star shared details of her upcoming operation in a video made by the MAFS Funny Instagram page, who are documenting her trip alongside fellow MAFS bride Awhina Rutene. 

The 35-year-old is set to undergo rib sculpting, also known as the 'Barbie waist' procedure. 

The body-contouring surgery, which is not yet available in Australia, involves reshaping the lower floating ribs to narrow the waist without removing bones. 

In defending her decision to have work done, Bec told MAFS Funny that she is not confident in her looks and would get extensive surgery if she could. 

'I've got a lot of loose skin. This is the most vulnerable I am ever going to be because this part of me that I can't stand sometimes looking in the mirror,' she said. 

'Your body your choice. If you feel comfortable with it, f***ing do it. So why are all these Karens coming at me?'

Bec said that 'no one wants to look like me' and compared herself to Sid the Sloth, a cartoon character from the animated feature film, Ice Age. 

She added that people often tell her, 'Get your teeth done. Get your mouth done and get your jaw done. Get your teeth done. Get your nose done.

'Like trust me, if I could I would.'  

Bec is no stranger to plastic surgery, having undergone a jaw procedure at the age of 21 to correct a chin defect. 

There was prompt backlash in the comments section of the video, with many fans and fellow MAFS stars concerned about Bec's decision to get the procedure. 

'Call me Karen, but getting the most insecure women to go and permanently change their bodies like this while promoting it... shame shame shame,' wrote Married At First Sight bride Domenica Calarco. 

One fan ranted: 'Slap the two most insecure women from MAFS for a chance to bloody have RIB SURGERY. This is so far beyond ridiculous. I'm shaking my head. Call me a Karen I don't even care, because you're literally not aiding women at all. 

'You're perpetuating the narrative that women feel the need to change their bodies so dramatically, just to love themselves. The loose skin, I can understand that. But contouring ribs?! Come on. Sounds like slaughter.'

One more wrote: 'I'm so open to people doing whatever they want with their own body, but Bec this is so worrying. If you want to do it that's on you, but this seems like a dangerous surgery to be promoting.' 

'These influencers really need to be held accountable for contributing to insecurities in young and impressionable women and normalising things that really shouldn't be normal!' said another person. 

They added: 'If you are so insecure that you literally need to change your literal skeleton, that's awfully sad but please please don't perpetuate these unrealistic and dangerous beauty standards.'

Someone else said: 'Repositioning your ribs isn't going to solve a loose skin issue. Sorry but this is just mental behaviour.'

'Changing your skeleton is hot now? F**k that. Might do something crazy and just love myself instead,' wrote one person. 

Bec replied to that comment personally, writing: 'Nah, it's called my body, my choice.'

Married At First Sight star Beck Zemek chimed in: 'If I said yes to the amount of free plastic surgery I've been offered since MAFS I would be botched by now. 

'I don't believe you should do something you never had insecurities about before just because it is presented in front of you... Girls you're breaking your rib cages.'

Others were supportive, with MAFS star Jacqui Burfoot writing: 'This comments section is so mean! I'm all for freedom of body, choice and speech. 

'Education is always the answer - in this case people should be aware of the real risks and how many ladies die from these kinds of surgeries particularly offshore. 

'The ladies are perfect, but they can also do what they like - they are adults!'

Awhina Rutene also took to the comments section to defend herself and Bec.  

'I feel like there's been a wild misconception about the type of MINIMALLY invasive surgery we're getting... Similar to when waist trainers are a thing, we're getting keyhole surgery, so a bandaid is what we're left with,' she wrote. 

Awhina said the surgery will 'contour and angle our lower ribs to create an hourglass.'

'You can choose how drastic (it will be). I'm getting a 5cm difference that I will hold in place with a corset. I am NOT the blueprint for anyone's life but I also want to be transparent with my audience when getting anything so people don't set unrealistic goals for themselves,' she added.