"I have had to work harder than everybody else because of my size," she told Harper's Bazaar UK. "I've always had to suck it up.
"If you're the kind of person who's never been glamourised in fashion then you have to justify why you're meant to be there through your efforts."
However, despite the obstacles she's faced, Graham prefers to not think of her journey as "hard".
"Has it been hard? I'd prefer to say that it's been rewarding," she stated.
The model has always been frank about her body image, in the hope that she may inspire others to be the same.
"I've always been very honest in sharing the insecurities I have. Cellulite, back fat... It opened a door for other women to share their insecurities," Graham said.
"If we all feel the same way, why are we stressing about it? I've never gone to therapy but having these conversations really does help."
In March, Graham called out publications which airbrush models while making an appearance on Australian talk show The Project.
The model warned that there's "still so much retouching that's happening, trying to change who we are", adding that people have tried to "manipulate" her body for years.
Graham also discussed the use of the term "plus size", explaining why she's not a fan of the phrase.
"Why do we have to describe a woman because of a number inside of her pants?" she said.
Graham's new interview is in the July issue of Harper's Bazaar UK, on sale from Thursday.
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