The one thing Martha Kalifatidis won't post on Instagram

The Instagram star admitted the constant criticism was taking its toll. Photo / Instagram

She regularly shares racy bikini shots and has even posed nude, but there's one thing MAFS star Martha Kalifatidis will never divulge.

Since appearing on Married At First Sight Martha Kalifatidis has quickly become one of Australia's most followed Instagram personalities.

The former makeup artist has more than 290,000 Instagram followers for which she regularly shares racy bikini shots with and even posed nude to celebrate her one year anniversary with boyfriend Michael Brunelli.

But Martha says there's one type of picture she will no longer post as she opened up to news.com.au about the toll online bullying, also known as "trolling", has had on her.

The MAFS star has a seriously enviable figure. Photo / Instagram

And posed nude to celebrate her one year anniversary with boyfriend Michael Brunelli. Photo / Instagram

"I'm embarrassed now to take a photo with my toes in it, because I had photos with my feet in it and people just went on and on about it." she said.

"I'm like, 'they're feet man, when would they ever look good?' They're feet."

While Martha might ooze confidence in her Instagram photos she admitted being on reality TV has affected what she posts.

"I feel like me a year ago or two years ago I did have so much more self-esteem and (I was) probably a little bit more confident," she said.

"I'd just be in a bikini and I wouldn't care, but now I feel like people are going to really try and tear me to shreds."

But while Martha tries to "roll with the punches" when it comes to life in the public eye, she finds it hard when people target her loved ones.

"Some of them are really nasty. When they attack my family and stuff like that, and Michael … I take it personally, I can't handle it," she said.

"When they come for me it's fine, I can brush it off. but I know like that it can effect some of the people around me. It's hard, you know, it's hard."

When it comes to Instagram Martha also admits what other influencers refused to acknowledge: that most of what appears on the social media app has been altered.

The Instagram star admitted the constant criticism was taking its toll. Photo / Instagram

"I do photoshop; I'm not afraid to say that. I feel like every single image that you see in a magazine or anywhere, any iconic photo that you've seen, that you've saved, that you've liked it, it's been edited," she said.

"It's just part of making an aesthetic photo. Who wants to see pores in a photo? I don't."

Martha said she didn't understand why editing pictures was considered such a negative when it was such a widespread practice.

"I just don't know why people think it's shameful to edit and smooth out a photo. Like, everyone does it. I know all my friends do it," she said.

"I've never been someone to say, 'No, that's what I really look like.' Hell, no. I've edited it, yes!"