How this 20-year-old influencer wound up sleeping on the streets of Sydney.

Take just one look at Alli Simpson’s Instagram account and it’s clear the 20-year-old lives a glamorous life.

The singer and influencer admitted to knowing little about homelessness, but agreed to swap her Los Angeles apartment and everything in it for 10 days of living on the streets of Sydney.

Alli is one of five privileged Australians to take part in the second series of SBS‘s Filthy Rich & Homeless, with the aim to raise awareness on the homelessness crisis. At the last census, more than 116,000 people were without a home.

Alli and her counterparts – Cameron Daddo, Skye Leckie, Ben Law and Alex Greenwich – were stripped of their possessions, handed secondhand clothes to change into and a sleeping bag and sent out onto the street.

Speaking to Mamamia, Alli said she took part in the show as a way of using her platform for good and to make a difference. She was nervous and fearful going in, and nothing could’ve prepared her for the experience.

got something to share.. recently I embarked on the most difficult experience of my life #FilthyRichAndHomeless tune in on @sbs_australia 8.30pm AUG 14th/15th & 16th you have no idea.. ????

A post shared by ALLI SIMPSON (@allisimpson) on Jul 9, 2018 at 1:13pm PDT

“We weren’t told anything going into it because it was supposed to be a real, immersive experience,” she said.

“Going into it I thought I was strong and I could get through it, but once I started and was out on the street it was really real and really confronting and a lot more difficult than I thought.”

Being a young woman on the streets naturally caused fear for both her and her family, but for Alli isolation was the biggest challenge.

She had never struggled with anxiety before, but had an anxiety attack on her third day on the street.

“The hardest part I think was definitely being confronted with being alone… You don’t have anybody else, you don’t have anyone to turn to or anything to turn to.”

“It’s a feeling that I’ll never forget and one of the most awful feelings I’ve ever experienced,” she said.

The experience almost became too much for her and she came very close to pulling out of the show on her third day of homelessness, but it was the day-to-day interactions with others that kept her committed.

“The moments that got me through was when I was talking to other homeless people or having conversations with homeless youth,” she said.

“Seeing the small differences I was making in each of these individuals lives, that’s what kept me going because that was why I signed up.”

Alli was the only one of the show's participants not to receive any money or help from members of the public, and this really damaged her "hope in society".

"I'm wondering whether because I was young, because I was a young girl that seemed sad and vulnerable, the judgement of them thinking 'oh she's run away from home', or 'oh she just wants the money for drugs'. I felt that judgement from people and it was really, really hard for me," she said.

"It was just like you were completely invisible. People would just walk straight past you, or you would make eye contact with them and they wouldn't smile, wouldn't stop, there was no interaction from anybody and that really broke my heart."

It was eye-opening for her to realise the only generosity she experienced during her 10 day experience was from other homeless people.

Alli returned to L.A the day after filming wrapped and is back posting selfies on Instagram and living her 'normal' life, but she isn't going to forget her time on the street.

"As soon as I walked into my apartment I just burst out crying," she said about her return after the experience.

"I was looking at all of my stuff and all of my things that are just so unnecessary and all these things I just would've killed for out on the street that I had, and this was my life. I was thinking about all the people I met along the way and they're all still there in the awful position and I'm here back in my life that I'm very happy in. That was the really difficult part about coming back."

"I've realised what a big issue this is, and the things that need to change. It's a topic that nobody really likes to talk about and nobody really knows how bad it is and how difficult it is... For me, now I want to try and make as much of a difference as I can and raise awareness about the issue."

"It's just changed my perspective on life you know? I'm much more grateful and humbled."

Filthy Rich and Homeless airs over three nights – Tuesday 14, Wednesday 15 and Thursday 16 August on SBS from 8.30pm. A special live studio program will air directly after episode three.