Luckily, things have come a long way since then, with more plus-sized brands coming into play in Australia, which helped Casey feel a little bit more confident in herself.
Feeling comfortable in her own skin is something she's had to figure out on her own terms, as she tries to navigate blocking out all the "noise" of people's judgement.
"There was always the social pressures as to what society expected me to be so it's always been a challenge and I think for anyone it will," she says.
"Somehow in all of that hoo-ha finding the confidence within myself to just ground myself and go 'okay, how are you feeling and what would you like to do about it?'."
The 33-year-old also describes confidence as a "constant battle", where she goes back and forth between finding it and then losing it.
But it's taken years of just self-love and not being hard on herself that Casey has finally been able to have that confidence in her "back pocket" for her to turn to when her own insecurities shine through.
"That little voice inside your head will always be the nastiest voice and it's sad that it's always your voice but I think it's just learning to shut that down and to identify and to really just accept who you are in all of your flaws and faults and just be happy and find the little things that make you happy," she says.
"It takes a lot of hard work and a lot of days you're just like 'I'm done, I can't be bothered' but finding that motivation and just working through and understanding and if you don't understand ask questions or do your research."
It's something that has led Casey to take part in SBS’s new series, What Does Australia Really Think About..., where she hosts an episode exploring the nation’s views on obesity.
It's a space where Casey wants to be "vulnerable" in and wants to encourage viewers to start having more conversations around the topic.
"There's lot of talk and stigma around bigger people and obese people and 'maybe they should just stop eating'," she says, referencing to some of the things people often say.
"This series really allows us to dive deeper and dig deeper and find out the whys and the statistics and what people really think and how people really feel and I think that's really important to have those new conversations injected into the world.
"I think now is the time to deal with things and in the world that we're moving into I think it's going to be so important to just try and get our bodies healthy and go in towards a better light and a better life," she says.