Facebook Twitter Pinterest Tess Holliday: “I am fat, so it’s kind of silly to get mad about it.” Photograph: Sergiy Barchuk for the Guardian

It’s always satisfying to witness a figure of speech made real. “Stopping traffic”: this is precisely what Tess Holliday is doing. Smouldering against a wall on a street in Red Hook, Brooklyn, thronged by the mini entourage of a professional photo shoot, she’s dressed in a corset and black cape, like some kind of vampish, couture superhero. It’s not going unnoticed.

“Keep driving, assholes,” she yells, making a scornful, chivvying motion at the dawdling cars and their gawking drivers. “Never seen a fat girl in her underwear before?” We all laugh, but she doesn’t smile. It’s a sour look she’s shooting them, more pissed off than triumphant. But maybe they really haven’t seen a fat girl in her underwear before, at least not in such glamorous trappings. Even though the average dress size in the US is a 14 (a UK 18), style magazines continue to be overwhelmingly peopled by the very thin, very tall, white and young.

In January, when she signed with the British agency Milk Model Management, 29-year-old Holliday became “the first size 22 model” (a UK 26). Since then, her name has barely appeared without that phrase. It’s a problematic tagline, not because it’s untrue (there has never been a woman this large working as a professional model) but because it entrenches her difference, making more extraordinary the thing that she wants to become more ordinary.

Holliday has a retroussé nose, ready-pouted lips and the sort of luxuriantly wavy, princessy auburn hair that demands the word “tresses”. But it’s less her very gorgeous face that makes her remarkable, and more the size of her body, which she’s fine with being called plain “fat”.

“To me it’s just a word, but it wasn’t until I discovered the body positive community that I became OK with it. I’ve been called fat my whole life,” she says. “I am fat, so it’s kind of silly to get mad about it.”

Holliday has close to a million likes on her Facebook page and nearly 800,000 followers on Instagram. Each blazingly forthright declaration she makes on social media reinforces her status as an inspirational figure defying the scrutinising and policing of women’s bodies. She recently tweeted: “To the people that fight on my social media: I don’t give a fuck. Get a therapist, phone a psychic or eat a fuckin’ burger... grow up.”

Holliday on Instagram with her fiance Nick. Photograph: Instagram @Tess_Holliday

My friends would tell me, There’s no way you’re going to get a nice guy and a hot guy

There is, of course, a paradox here. In becoming a full-time model she has entered into an industry that, by definition, does just that – scrutinise women’s bodies. However radical she is in terms of her size and attitude, her job is still all about her appearance, about being looked at and judged on the way she looks. This does not seem to bother her. “Isn’t it better to have a voice within the industry that’s speaking against all that stuff, instead of nobody doing anything at all?” she asks. “Do I like what the media does? No, but I’m very outspoken about that. So, it’s a pretty simple answer.”

When you look at some of the 763,109 (and counting) Instagram posts tagged #effyourbeautystandards it does indeed start to seem more simple. Holliday started the hashtag in 2013, furious and defiant over the volume of online bullying she received for posting, for example, pictures of herself in bathing suits. She’s been overwhelmed by the outpouring of feeling, not just from bigger-figured women, for whom posting a picture of themselves is a transformative, courageous act, but from, for example, young gay men struggling with body image.

We’re in a cafe, finally sitting down after a six-hour shoot that’s had Holliday traipsing blocks in oppressive heat and then a rainstorm. Throughout, she’s been a hilarious corrective to the notion of models as mute and biddable clotheshorses. At one point, an African American guy, middle-aged, said something appreciative as he walked by. “What do guys think they’ll achieve by yelling something?” she asked, shifting her weight and adjusting the cape primly. “They’re like: ‘She’ll love this, I’ll definitely get her number.’” A pause, and then she added, with some satisfaction, “I do admit that black men love me. I always forget that, and then I come to a black neighbourhood and I remember.” And no one quite knew what to say. Later, finally and effortfully manoeuvred into some lethal-looking Christian Louboutin stilettos, adding height to her 5ft 5in, she’d calmly told the photographer: “If you’re not shooting my shoes, I will fuck you up.”

Holliday has a hugely influential online presence, helped in no small part to the #effyourbeautystandards hashtag she started in 2013 in response to online bullying she received for her selfies.

Throughout this her fiance, Nick Holliday, a sweet and talkative Australian with a big slab of hipster beard, has been on hand, anticipating and meeting her every need (a snack of fruit, a glass of water, some sunscreen). They’re not married yet, but she adopted his name when she signed with Milk this year. Before then, her professional name was Tess Munster, a surname she chose because she liked The Munsters, the classic TV show about the family of benign monsters (“that’s pretty much all there is to it,” she says).

Now, with her hair scrunched back in a bun and her face meticulously wiped clean of makeup, she orders a pain au chocolate and a hot chocolate and takes a call from Rilee, her nine-year-old son, whom she had with a boyfriend when she was 20 and working in Walmart. She’s no longer in touch with his father. Once she hangs up with Rilee, she takes a sip of the hot chocolate.

“Everyone has their vices,” she says, “but mine are visible.” As in, comfort-eating, for which she refuses to apologise. “If I shot all day and I want a fucking hot chocolate and a chocolate croissant I’m going to eat it. Am I going to eat it for breakfast, lunch and dinner? No. Is it OK to do it? If you want. But, you know, no one is coming at celebrities for smoking two packs of cigarettes. Or people who post a photo with their drink at the end of the day. So why is it OK to do that to me? Life is shitty, so why would you judge somebody for dealing with it in the best way they can?”

When you consider Holliday’s childhood and adolescence, you can understand why she might think the world “shitty”. She grew up in the southern US and her family moved, she estimates, at least 40 times before she turned 10. When I ask why, she responds bluntly: “My dad is sketchy.”

Her mother left him when Holliday was a small child. She says he used to call her fat all the time. “He’d say I had a pretty face but he would belittle me and tell me that I couldn’t do certain things because of my size.”

Facebook Twitter Pinterest Tess Holliday: “No one is coming at celebrities for smoking two packs of cigarettes. Or people who post a photo with their drink at the end of the day. So why is it OK to do that to me for eating?” Photograph: Sergiy Barchuk for the Guardian

She has now severed contact with him. “When you become an adult and you have a choice of who to have in your life, if someone’s hurting you and making you feel bad, then they shouldn’t be in your life, even if it’s a family member. To me, they don’t have any privileges. I kept giving him chances and he kept treating me poorly, and I just thought, ‘You’re not allowed to be in my life.’”

It was another man, though, who messed up her family’s life even more. When Holliday was nine years old, her mother was shot twice in the head by her fiance, who was charged with attempted murder. Holliday and her brother subsequently moved into a trailer in her grandparents’ back garden while her mother recovered. (She remains paralysed and disabled.) Holliday relays these facts so dispassionately that I’m astounded.

“I mean, it will be 20 years ago on 22 June,” she shrugs. “So, you know, it happened a long time ago. And my mum is here and she annoys the shit out of me. She’s still in a lot of pain, she still suffers, but she’s here.”

She’d attempted modelling before. They’d told her she was too short and too big, even for plus-size modelling.

It was her mother who supported her decision to drop out of school aged 16, by which point her daughter’s bullying – for her weight, pale skin and for having a disabled mother – had become intolerable. “I went in my first day of junior year and it was the same shit and I just thought, I’m not doing this any more.”

She had little idea what she wanted from her life, only that she wanted to get as far away from Mississippi as she could. She mentions the Tim Burton movie, Big Fish. “I love that movie because he was a big fish in a little pond and he wanted to get away. And that’s kind of how I felt.”

After a stint in Alabama she moved to Seattle with a then one-year-old Rilee, three suitcases and $700, finding work as a makeup artist. She’d attempted modelling before, when she was just 15 and travelled all the way to Atlanta for an audition. They’d told her she was too short and too big, even for plus-size modelling. So when she posted some pictures of herself in 2009 that she’d had taken for Rilee’s father, on a site called Model Mayhem, she didn’t think much of it. Days later, a casting agent called, and soon her face was on buses and billboards, and in ads for Heavy, a documentary about the weight loss struggles of the morbidly obese. (She’s almost unrecognisable in that image, staring morosely up at the camera under the words, “Losing is their only hope.”)

Tess Holliday: “My dad used to say I had a pretty face, but he would belittle me and tell me that I couldn’t do certain things because of my size.”

An inauspicious beginning, then; but a few years after this she moved to Los Angeles and began getting more modelling work, while working in a dental office. Now, she’s appeared in Nylon magazine and on the cover of People magazine, shot a campaign for Benefit makeup, been named by Vogue Italia as one of the world’s most influential plus-sized models and has worked with the legendary photographer David LaChapelle on a forthcoming, still secret project. She left her job at the dental office last year.

Her images are unfailingly stunning, but her power has as much to do with her role as a campaigner and personality as with her photogenic qualities. Few supermodels, however, attract the kind of online nastiness she does. She tries not to pay attention to this, nor to the fandom.

“I used to look at Reddit quite often,” she says, “but when Nick sees me going on it he will take my phone away from me. You just click on any article that’s written about me or any photo that’s posted of me and there’s a whole discussion about my health.” Much of it is “concern-trolling” – in other words, a kind of fat-phobic shaming masquerading as care, which one of her fans skewered in a tweet: “My only concern for @Tess_Holliday’s health is all the germs she’s gonna get in her eyes from wiping her tears with $100 bills.”

Holliday loved that. “It was so funny,” she says. “It’s not accurate! I have, like, $4,000 in my bank account right now, because I’m waiting to get paid from people.”

She happily admits that she’s making way more money than the $20,000 salary she made at the dental office. She’s feeling extravagant enough, for example, to buy her best friend’s new baby a pair of Gucci sandals. “So stupid,” she laughs. “She was like, ‘No no no!’ But I said, ‘No, take them… you can give them back to me when I have a kid.’” Which she wants very much. She and Nick met online after he sent her a message on Tumblr telling her that he loved how she inspired other women. She was smitten; he moved to the US from Melbourne.

“I was like, this guy’s never going to give me a chance in hell because he’s so hot. Because I’ve never really had good-looking boyfriends before. My friends would always tell me, ‘There’s no way you’re going to get a nice guy and a hot guy – you’re fat, you need to settle for one or the other.’ I told them, I deserve both.”

Facebook Twitter Pinterest Tess Holliday: “Miss Piggy’s a big girl, and glamorous, and people think it’s silly when I say she’s a role model to me, but she was.” Photograph: Sergiy Barchuk for the Guardian

Her fiance’s acts of devotion throughout the day include peeling a panty liner sticker from the sole of her sandal that’s been trailed in from a Brooklyn street. At one point he praises the firmness of her ample behind. “You can give it a good old smack,” he says genially, bringing a loving hand to his betrothed’s bottom. She ignores him.

When they first met in person, Holliday admits that, “I wasn’t very nice to him, just because I had never had somebody treat me well before and I didn’t know what to do. So I treated him very badly. Don’t we all have daddy issues, though? I dunno,” she says. “I see my friend Nadia, who’s a plus-size model, post pictures saying how much she loves her dad and I’m like, ‘I don’t even know what that’s like.’” She draws a biscuit out of her bag and gives it an experimental nibble. “I’m trying to see whether this is worth saving or not,” she explains.

By her own admission, she’s easily distracted. When I ask about her tattoos, though, she snaps back into focus. “All the women on my arms, none of them give a fuck,” she says. They include Mae West, Dolly Parton and, resplendent on her right forearm, the porcine features of another feminist hero: “Miss Piggy’s a big girl, and glamorous, and people think it’s silly when I say she’s a role model to me, but she was. She was sassy and sexy and people noticed her, and she was big and she didn’t care.”

Miss Piggy is a force of fabulousness, a Personality, capitalised. Holliday, too, knows that she’s something bigger than a plus-size face and body. “I don’t consider myself just a model,” she announces, with all the prima donna attitude of her favourite pig. “I’m a brand.”