Jackie ‘O’ Henderson shows off her incredible weight loss in a tight black dress as she plays a prank on co-host Kyle Sandilands

She has lost an impressive 18kg. 

And Jackie ‘O’ Henderson showed off her incredible slimdown in a tight black frock on Tuesday. 

The radio host, 48, looked super slender in a clingy maxi dress as she played a prank on co-host Kyle Sandilands and their KIIS FM staff. 

She teamed the summery dress with a pair of sandals and a cream designer handbag.  

Jackie took to her Instagram stories to demonstrate the effects of her ‘Invisible danger prank.’ 

She was seen leading Kyle, 52, and other team members outside when all of a sudden she stopped and started screaming. 

Kyle was startled, along were the others, as Jackie ran away.

After composing himself, Kyle said ‘What the f**k, there’s nothing here,’ before Jackie returned and started laughing. 

Jackie then repeated the prank in the KIIS FM offices, screaming as she pretended to see something terrifying, which caused some of her team to run out of the office with her.

Jackie is seen leading Kyle Sandilands (pictured left) outside when all of a sudden, she starts screaming. Kyle is startled, as Jackie runs away. After composing himself, Kyle says ‘What the f**k, there’s nothing here,’ before Jackie returns and starts laughing

The blonde beauty recently spoke about her new diet amid her weight loss, admitting she often skips breakfast, a practice known as intermittent fasting.

She also avoids carbohydrates, and satiates her hunger throughout the day by snacking on pre-cut pieces of steak.

‘I cook steak and slice it, and then I’ll just have a little sliver of steak if I’m hungry,’ Jackie said.

The blonde beauty recently spoke about her new diet, admitting she often skips breakfast, a practice known as intermittent fasting

She also avoids carbohydrates, and satiates her hunger throughout the day by snacking on pre-cut pieces of steak 

She resists splurging on high-calorie foods for lunch, opting to eat just ‘three little slivers of steak’ and a few Vietnamese rice paper rolls containing fish and cabbage.

Kyle was shocked by her small portion size, telling her: ‘A dog would eat more!’

For dinner, Jackie usually eats vegetables and a protein such as chicken or red meat.

In between meals, Jackie treats herself to smoothies and Starbucks Frappuccinos, a type of blended ice coffee drink.

Jackie hasn’t always followed such a restrictive diet.

In February, she told Woman’s Day she used to binge on pizza, sausage rolls and microwave meals from the petrol station before she took control of her health.

‘I was eating a lot of food that I could get in a hurry. You know, pizza and sandwiches and just takeaway, I wasn’t cooking myself,’ she said.

‘And I think it’s always best when you know what you’re putting into your body. I just got really lazy.’