At size 24, Los Angeles-based model Tess Munster is the largest plus-size model to be signed with a mainstream agency. A strident “body-positive activist”, who has appeared in Vogue Italia and been photographed by David LaChappelle since being scouted on Instagram, the 29-year-old has now been signed up with the Curves division of Milk Model Management, and will star in adverts for plus-size clothing retailers Yours and Simply Be.

You’re the first woman of your size to be signed to an agency. Congratulations. Does it bother you that most of the focus is on your size?

I don’t mind talking about my size. What’s frustrating is that we haven’t been focusing on making history in an industry that had a set look. Still, people talking about it – good or bad – is good.

How did you first get into modelling?

I went to a casting when I was 15 but I was told I was too short and too big. I was a US size 16 (UK 18/20) and I’m 5ft 4in. It was a little discouraging – I stopped trying to pursue modelling and it was only when I retrained as a makeup artist, working at fashion shows, that I started getting interested again. The truth is, I didn’t want to do anything else.

You have always been what is considered plus-size. Did that ever deter you?

Everyone said I had a pretty face, so it seemed possible. I just didn’t know there was such a thing as a plus-size model. It was only when I saw a picture of Mia Tyler [one of the first plus-size models in the 1990s] that I realised I could. I am lucky that I have a supportive family, partner and friends. That I got signed? Well, the reaction has been overwhelming.

How so?

I got a lot of comments on Twitter, Instagram, even some letters. Some people were excited, some people called me fat and said I was too big to be a model. I spent a long time fielding through the reactions. Ultimately, in my eyes, my being signed is changing an industry that needed to be changed.

Are you surprised that you are the first model of your size to be signed?

It does seem ridiculous that it was considered news. But it’s one of the best things that has happened to my career. It has given me the opportunity to work in a different playing field. Overall, companies think that consumers want to see one skin colour and one size – which is why we tend to see a lot of the same sizes.

After your experience as a teenager, were you ever tempted to diet ?

I was never tempted to lose weight. Everyone around me was on Weight Watchers, but it never appealed to me. I have never been one for changing yourself to make someone happy.

Has your size ever bothered you?

I think we all struggle with body image. Everyone has an issue with some part of their body. It’s hard when you’re a teenager to see people who don’t look like you succeeding. In mainstream magazines – even now – no one looks like me.

Looking at some of the spring/summer 2015 trends – take bohemian or the 1970s influence – do you think there’s a place for bigger women in mainstream fashion?

We do have a place in fashion, but not many designers are willing to give us the opportunities. But certainly with the 70s trend, there were plus-size fashionable women during that period – Mama Cass, for one. I own a great 70s dress. A big change for me was when one of my friends – Denise Bidot – was the first plus-size model to walk New York fashion week and London fashion week. It’s a good sign. Seeing her do that, it feels like we do have a place and people are listening.

It’s true: fashion seems to be taking baby-steps to embrace diversity – look at Serena Williams on the April cover of US Vogue.

The reason it’s socially acceptable to show Williams is because she is considered fit. For a long time, someone like Rebel Wilson was considered unfit. That said, she’s on the May cover of Elle, full body. It made waves.

Before Rebel, plus-size stars had always been close-cropped. Look at Adele on the October 2011 Vogue cover or Lena Dunham on the February 2014 cover of US Vogue.

I have no idea why they choose to crop, but it doesn’t seem like a coincidence to portray them that way.

There was a big hoo-ha here about the #droptheplus campaign, asking that we drop the term when describing bigger models. Where do you stand on it?

To me, we’re debating a term that has never been used in a hateful context. I’ve always been called plus-size. It’s not a negative thing. It’s what I am. It’s like saying I should be offended at being called a redhead. It is just a fact. I understand I have quite a progressive viewpoint on this. We could do more with our time than debating that word. But no one is calling me a fat model.

Do you think fat is a negative word?

I don’t think it’s negative – but I know that 80% of the world would disagree.

Tess Munster refers to herself as Tess Holliday and can be found tweeting at @Tess_Holliday

• This article was amended on 16 April 2015. An earlier version gave the UK conversion of a size 12, rather than 18/20, for Tess’s US dress size 16.