The Australian star, who quit her role as Rachel in Packed to the Rafters earlier this year, is currently trying to launch her Hollywood career and has noticed the "thin" culture in Los Angeles.
Marais told The Daily Telegraph: "I did notice that while I was over there that everyone is particularly slim compared to the Australian industry. But I didn't necessarily feel that pressure. I try not to pay attention to that stuff.
"I am only interested in what I think of myself and my happiness in who I am. I don't feel like I have to respond to any of that or buy into it at all."
She revealed that she is not scared to "go ugly" for the sake of a large acting role, saying: "I'm just dying for the chance to shave my head and do a completely meaty Charlize Theron in Monster-type role."
Marais also said that she "needed a good break" from Packed to the Rafters but is "definitely open to going back" in the future.
The actress, who recently lost out on a Silver Logie award to on-screen mother Rebecca Gibney, came under scrutiny last December for apparently shedding lots of weight, but her representative described her as "fit and healthy".