Instagram Star Says She Quit Social Media to Be a Positive Role Model for Younger Sister

— -- Australian Instagram star Essena O’Neill, who shocked her legions of fans when she announced she was quitting social media this week, said one of the reasons she quit was because she wanted to be a positive role model for her younger sister, who is 14.

“We were talking and I said this thing to her, 'when I was your age, you know I looked at models and I remember actually measuring my stomach and looking in the mirror thinking, am I like them? Why aren’t I like them?' And she bursts out in tears and said, ‘I do that,’ and it was just like, far out, you know?” O'Neill told ABC News' “Nightline” in an exclusive interview via Skype from Australia.

O’Neill, 19, who had more than 700,00 followers on Instagram and 260,000 subscribers on YouTube, posted a shocking confession on YouTube two days ago, announcing that social media had made her “miserable” and that online and mobile-sharing platforms can be unhealthy, so she wanted to shut down all of her accounts.

“What I’m saying isn’t revolutionary but I just think it’s a discussion worth having with how much value we put into just putting photos of ourselves online," she told “Nightline.”

"Nightline" made multiple attempts to reach O’Neill for further comment since talking with her Monday, but none were returned.

O’Neill deleted most of the thousands of photos on her popular Instagram account and changed the captions on the few she left up to reveal what she said was really going on in the photo. In one photo where she is featured wearing a white gown, she changed the caption to say, "NOT REAL LIFE -- I didn't pay for the dress, took countless photos trying to look hot for Instagram." In another photo of her in a swim suit, she re-wrote the caption to say, "NOT REAL LIFE -- took over 100 in similar poses trying to make my stomach look good."

“I spent five years wishing I was this perfect person online and I spent three years every day working really hard at it and I think if people understood just the amount of effort and time that goes into perfecting your life like that and being consistent that I think that wouldn’t be aspirational. I think the reality is quite sad,” O’Neill told “Nightline.”

O'Neill said she started using social media when she was 12 years old. Once she had gained a large following, O’Neill was paid for posting pictures of herself on social media with certain products or wearing certain outfits, unbeknownst to her followers, she said. O’Neill is also under contract with international modelling agency IMG.

“Like what paid Instagram posts? And then I was like, 'What? People don’t know this?' I just thought it was a joke and people could be like, ‘Oh, that’s why she quit.’ It’s not real life,” she told “Nightline.” “For me, I don’t feel good on social media. But that’s just me personally, and that’s just a personal decision I’ve made.”

Her “take down” of social media earned O’Neill an outpouring of support online from all over the world, including from celebrities like Sophia Bush, who posted on Twitter, “My GFs and I spent the better part of yday discussing Essena O'Neill's awesome serving of social truth.”

Some people, however, have questioned her true motives. In her last video on YouTube, O’Neill says if her message “is of value to you, then yeah, please support me because I can’t afford my own real life.”

Her detractors have posted YouTube responses saying O’Neill’s regret is fake, including two of her former friends, Nina and Randa Nelson, twins from Los Angeles who are also social media stars.

But for now, O’Neill said money and publicity weren’t her goals. She said she wants to encourage others to focus on their lives and develop real relationships.

“Give yourself a break and see what happens," she said. "Experiment, talk about it with people in your real life. Don’t just sit on your phone, reading article and then replying, talk about it to people around you, talk about it to yourself.”