Kyle Sandilands takes a dig at Jackie O during Blake Lively's appearance on their radio show.

KIIS FM’s Jackie O has once again been weight shamed live on air. By her co-host.

This time, Kyle Sandilands mocked her for failing to lose weight after giving birth to daughter Kitty five years ago.

During an interview with actress Blake Lively, 28, to promote her new film The Shallows, Jackie explained that a group of her and her colleagues had started a weight-loss club.

“We’ve got a ‘fat club’ going on where we’re all trying to lose weight for the next eight weeks,” Jackie said.

“As a member of the ‘fat club’ myself, have you got any advice that you can offer on losing weight quite fast?”

Lively said she maintained a balanced diet but cut out gluten and soy, so that she was no longer eating any processed foods.

A photo posted by Jackie O (@jackieo_official) on Jun 28, 2016 at 4:32am PDT

That’s when Sandilands jumped in, telling his co-host, “Jackie, I think you’re asking the wrong family for advice, like you’ve really set the bar high for yourself.”

“Eight months! Jackie’s on five years,” Sandilands exclaimed.

A photo posted by Blake Lively (@blakelively) on May 13, 2016 at 12:21pm PDT

When Lively commented that “you feel like you’re never going to get your body back again” after childbirth, Jackie said, “no, I still haven’t.”

Sandilands continued: “Jackie’s on five years and yeah, when are you going to start Jack?”

“That’s what I mean, I’m starting now,” she replied.

“Five years, that’s too late babe,” Sandilands said.

Lively tried to take a more encouraging tone, saying she believed body acceptance was first key.

“When I had a kid I thought, you know, this is what my body looks like now, I had a kid, that’s amazing, I earned this body. It’s not as good as it was before I had a kid but you know, you challenge yourself like that,” she said.

A photo posted by Jackie O (@jackieo_official) on Jul 19, 2016 at 2:23am PDT

Jackie O’s body has repeatedly been a talking point on the breakfast radio show.

Just two weeks ago, Sandilands appeared to take a dig at Jackie O’s weight.

When Jackie admitted she had never slept with an overweight person, Sandilands appeared stunned.

“You’ve never had a fatty?” he asked, Daily Mail reported. “How hypocritical of you.”

On this occasion, Jackie hurled an insult back at him.

“Have you had a fatty? You guys wouldn’t even be able to reach other,” she said.

And you might recall last month her own father fat shamed her on air, remarking that she had “stacked on the weight” and that she’d “let herself go.”

For what it’s worth, we think Jackie looks fab.

So how about we all agree that if you haven’t got anything nice to say, don’t say anything at all.