Katie Johnston, a recent bride on Married At First Sight (MAFS), says she lost 26 kilograms in three months and marked the milestone by slipping back into the wedding dress she wore on the show.
The 37-year-old told Woman's Day the transformation followed a DEXA scan that showed dangerously high levels of visceral fat and a bio-age older than her actual age — results that she described as a wake-up call to take her health seriously. Johnston said the decision to lose weight was about survival rather than appearance.
Johnston, who was paired with teacher Tim Gromie on the most recent season of MAFS, said her time on the show also exposed unresolved issues around self-esteem. She told the Daily Mail she had deliberately gained weight earlier in life as a form of protection after a violent rape when she was almost 21. "The weight became my protection — a barrier between myself and a world I no longer trusted," she said.
On the program, Johnston said she hoped her match would look beyond appearance, but was hurt when Gromie said he preferred "petite blondes." She described the remark as devastating and said it contributed to her decision to walk away from the marriage. "I never want to be in a dynamic with somebody like that," she said. "No matter what shape I am, I'm still good enough."
Johnston said the scan results forced a new perspective. "My bio-age was older than my actual age. The fat around my organs was a massive red flag," she told the Daily Mail. "That basically means early death. That was the shock that I needed to take this journey very seriously."
She initially tried weight-loss injections, including tirzepatide (marketed as Mounjaro), which is prescribed for type 2 diabetes and has been associated with weight loss. Johnston said early use left her fatigued and sick, and she temporarily stopped. She later resumed treatment with Mounjaro alongside a supplement she said reduced side effects, and credited the combination with restoring her energy and motivation to exercise.
Johnston framed the effort as a broader reclaiming of health and confidence. "This isn't about vanity," she said. "It's about survival." She said the rapid loss left her feeling stronger and more resilient and that revisiting the wedding dress was a symbolic moment noting how far she has come since leaving the experiment.
MAFS, which pairs strangers in commitment ceremonies and tracks their relationships on television, has prompted public discussion about the pressures contestants face on and off screen. Johnston's account highlights health concerns that can underlie visible weight changes and the role that medical testing and clinical guidance can play in prompting lifestyle changes.
Johnston has spoken openly about enduring anxiety over others' perceptions and the longer-term psychological effects of past trauma. She said watching herself on television revealed that she had not finished the personal work she thought she had, prompting the steps she has since taken.
Her statements about treatment and results reflect her personal experience; medical professionals recommend that people consult qualified clinicians before starting or changing weight-loss medication. Johnston said she hopes sharing her story will encourage others to seek help and prioritise their health.
Johnston's appearance on MAFS and subsequent interviews have been covered in Australian media, where she described the program as a turning point that forced a reckoning with both physical and emotional wellbeing. She said the combination of medical testing, therapeutic work and lifestyle change drove the rapid weight loss and accompanying boost in confidence.