'I'm not sure what's growing quicker, my friendship and trust with you or your waistline': Jackie O doesn't hold back as Kyle Sandilands celebrates 45th birthday
His weight has often been a point of discussion on their top-rating KIIS FM breakfast show.
And when celebrating Kyle Sandilands' 45th birthday on Friday, co-host Jackie O didn't miss the opportunity to bring it up again.
Reading an open letter dedicated to the outspoken shock jock, 41-year-old Jackie daringly joked: 'I'm not sure what's growing quicker, my friendship and trust with you or your waistline'.
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She went there: When celebrating KIIS FM co-host Kyle Sandilands' 45th birthday on Friday, Jackie O joked, 'I'm not sure what's growing quicker, my friendship and trust with you or your waistline'
King Kyle: The media personality has battled the bulge in recent years
She added: 'But it's been a joy to watch these things', and Kyle was quick to retort.
'A lot of bloody insults in here,' he said, a cheeky remark to which Jackie simply laughed.
And the back-handed compliments didn't end there, with Jackie also saying: 'You've obviously got it all - the top rating radio show, the young gorgeous girlfriend and a farm full on animals that lick their own genitals'.
She later added, '45's a significant number - it's your age, it's the number of cigarettes you smoke a day, and it's the number of times you've threatened to fire Brooklyn this week,' referring to newsreader Brooklyn Ross.
Living large: Kyle pictured in the US in July last year
Cheeky: The back-handed compliments didn't end there, with Jackie also saying: 'You've obviously got it all - the top rating radio show, the young gorgeous girlfriend and a farm full on animals that lick their own genitals'
Earlier on that morning, Kyle revealed girlfriend Imogen Anthony, 25, had jetted into Los Angeles to surprise him for his birthday.
Revealing they would be spending the weekend together, he moaned: 'It sounds like I'm going to be doing a lot of driving'.
'You sound like a real grandpa today. You are such a downer,' Jackie said.
Then Kyle himself acknowledged that his changed figure over the years is not his favourite look.
'My beard's grey, he said. 'Jackie showed me some old photos the other day, I felt really bad.'
Kyle's fluctuations in weight have been notably apparent over the years.
Big change: Australian radio personality Kyle Sandilands' look has certainly changed over the years, pictured in 2001 (L) and in 2015 (R)
Back in 2008 while appearing as a judge on Australian Idol, the outspoken personality spoke about his battle with the bulge.
'I'm fat myself. I have to lose weight, but every Sunday I tell myself I should and I'll start on Monday, but I don't,' he said at the time, according to The Sydney Morning Herald.
In 2011, his health issues took a more serious turn when he was rushed to hospital following a high blood pressure reading during filming of Australia's Got Talent.
But despite these health scares, it seems as though the radio star has struggled to alter his diet and lifestyle.
Blast from the past: Kyle revealed he 'felt really bad' recently when Kyle showed her some photos of him back in the day - the pair pictured in 2001
In the flesh: In 1997, Kyle appeared across a double spread for young women's magazine Cleo, wearing absolutely nothing but a golden crown
In 2014, his GP urged him to lose weight after suffering from a hernia, which caused him to vomit live on air.
Last year the host slipped that he had eaten six sausages for dinner one night simply because girlfriend 'Imogen didn't want them so I had to have hers too'.
Months earlier in May, he created a food diary which left co-host Jackie shocked by the findings.
'Two bacon and egg McMuffins for breakfast, one coffee with full cream milk and one Coke,' she revealed live on air while reading Kyle's day on a plate out loud.
Health scare: In 2011, his health issues took a more serious turn, when he was rushed to hospital following a high blood pressure reading during filming of Australia's Got Talent - pictured a year earlier in 2010
Serious: In 2014, his GP had urged him to lose weight after suffering from a hernia, which lead to him vomiting live on air - the radio personality pictured that very same year at Sydney Fashion Week
'A slice of carrot cake for morning tea and a whole box of Jatz with cheese and French onion dip and little bits of meat.'
Weeks later he stripped on national television while appearing on Channel Seven's Morning Show.
Proudly showing off his rounded figure, he explained to viewers 'This is an Australian man...I have been fat shamed over all the newspapers and magazines but Australia here it is.'
He went on to reveal he had become aware that something desperately needed to be done to improve his heath and figure, adding 'I am a mess and would like to live a bit longer'.
Tough: It seems as though the radio star has struggled to alter his diet and lifestyle - pictured with KIIS FM co-host Jackie O Henderson earlier this year
Habits: Last year the host slipped that he had eaten six sausages for dinner one night simply because girlfriend 'Imogen didn't want them so I had to have hers too' - the pair pictured in 2014
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