For the record, I wear what I want, when I want," she tweeted after the ceremony.
"News flash, it's MY body."
In an interview with Marie Claire earlier this year, Metz revealed she doesn't keep tabs on exactly how much she weighs.
"I don't worry about numbers. It just messes with my mind," Metz told the magazine.
She said that, as around a size 24 on top and an 18-20 on her bottom half, she was keen to lose some weight "to be proportioned. I carry a lot of weight in my stomach."
In the same interview, she revealed it was difficult to find designers who were willing to dress her for red carpet events despite the exposure it would bring.
"I'm so grateful for the designers who are excited - I remember growing up and having no options at all - but other designers haven't really reached out. I don't know why they think that their clothes lose integrity by being cut bigger. But it's their art. It would be nice if Valentino was like, 'Hey girl, want a dress?'" she said.