Campbell, who's modelled for brands including Chanel and Burberry and appeared on the cover of British Vogue, revealed on Instagram that she'd recently been subject to a contentious remark regarding her weight.
The British model shared a selfie of herself and artist Christabel Macgreevy on her Instagram story, showing the pair enjoying a hotel breakfast spread.
"When a brand says you are 'too big' to open their show so you get @christabitch round to have a slap up brekkie," Campbell wrote.
"By 'too big' I don't mean 'too famous'. I mean 'too fat'," she added in a second post.
A day prior, the model had also walked the runway for Italian fashion label Alberta Ferretti.
Campbell was named "Model of the Year" at the 2013 British Fashion Awards, an accolade that was presented to her by fashion photographer and frequent collaborator Tim Walker.
The 28-year-old was also dubbed an "icon" within the fashion industry by models.com last year.
Campbell has been critical of the fashion industry in the past, having last year called for models to be provided with private changing rooms when getting ready for shows.
The model explained to BBC Radio 4 that it can be "humiliating" for models to have to change in front of others.
"It's sort of quite jarring and then there comes a point when it becomes very normalised for you," she said.
“We operate within a culture that is too accepting of abuse, in all of its manifestations,” she wrote.
“This can be the ritual humiliation of models, belittling of assistants, power plays and screaming fits.
"We have come to see this as simply a part of the job.”
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