Model Simone Holtznagel shows off her alarming weight loss in a bikini

She recently shed an impressive 10kg after hitting the gym with the her personal trainer boyfriend Jono Castano.

And Simone Holtznagel showed off her dramatic weight loss on Monday as she posed for a post-workout mirror selfie before hitting the sauna. 

The Australia’s Next Top Model star, 29, showed off her tiny waist as she stripped down to a white string bikini, in a photo shared to Instagram. 

‘Sweatin’ out the weekend,’ she wrote in the caption.

It comes after her partner Jono insisted her slimdown was a result of a healthy diet and exercise and ‘not through starving herself’.

In the image, Simone covers her face but puts her trim figure on show. 

She posed up ahead of a sauna session at Jono’s gym Acero. 

Earlier this month, the blonde bombshell showed off her weight loss in a black lingerie set.

Earlier this month, the blonde bombshell showed off her weight loss in a black lingerie set 

Simone rose to fame on Australia’s Next Top Model

‘Wearing Nala Underwear making today’s digi day a little less daunting,’ she wrote in the caption.

Her lean midsection and toned legs were on display, as were her noticeably slimmer arms and defined triceps. 

Simone debuted her body transformation in August, after slimming down over the course of 10 months with the help of her PT beau Jono.

Simone debuted her body transformation in August (right), after slimming down over the course of 10 months with the help of her PT beau Jono. (Pictured left before her weight loss)

At the time, Jono denied any suggestion her weight loss was too drastic, telling Daily Mail Australia: ‘The way she got results wasn’t through starving herself; it was done through a structured program.’

Simone would eat four meals per day and her diet was ‘very well-balanced, incorporating all her macro nutrients in every meal,’ he explained. 

The socialite copped backlash after unveiling her body transformation, but said at the time she had been ignoring her critics.

Simone would eat four meals per day and her diet was ‘very well-balanced, incorporating all her macro nutrients in every meal,’ Jono explained. (Pictured left is Simone before weight loss in April 2020, and after weight loss in August 2022)

‘People have commented saying it’s ‘triggering’, and ‘before and after’ don’t belong in 2022…’ she told The Daily Telegraph.

‘I thought what we weren’t doing in 2022 was commenting on other people’s bodies,’ she added.

Jono and Simone met several years ago when she was one of the trainer’s highest-profile clients.

They initially kept their romance under wraps before going public in May last year when they were seen kissing at Mimi’s restaurant in Coogee.

Jono was previously married to fellow ACERO gym owner Amy Castano.

Jono and Simone met several years ago when she was one of the trainer’s highest-profile clients