Two years ago the American fashion blogger Gabi Gregg, 27, posted a picture of herself on her style diary, gabifresh.com, wearing a bikini. The post was written about everywhere, from Teen Vogue to the New York Post. It culminated in an appearance on the American television show Today, in which Gregg was asked to explain her decision to put the picture online. Why? Because she is a size 20, and, along with an increasing number of her fashion-hungry plus-size peers, she has had enough of hiding.

Her “fatkini” post (as she calls it) led to a contract designing bikinis for the American company Swimsuits For All , and a column for American InStyle. Now she has set up her own plus-size clothing line. Gregg is often cited as an inspiration by her peers, who aim to prove that, when it comes to style, size doesn’t matter.

“I knew it would be empowering for women to see a plus-size girl proudly wearing a two-piece,” Gregg says from her home in Los Angeles. While some commenters accused her of being unhealthy – or not fat enough – most responses were positive. “People told me that I’d made them feel it was OK to go to the beach again. Who knew something so simple could be so life-changing?”

The internet provides a space for plus-size bloggers to represent women they feel are ignored by mainstream media. “If it weren’t for ‘fatshion’ blogging, there’d be no images of fat women looking cool and wearing clothes anywhere,” says the LondonerBethany Rutter , 24, of the blog Arched Eyebrow. She thinks Adele falls into the “safe, pretty fat girl” category and that Lena Dunham is not plus size as she can wear “legitimate designer” or “straight size”, as plus-size bloggers often call it.

The Californian Amanda Allison, 28, of the blog Fashion, Love & Martinis , says, “The first time I saw a post by a blogger who had my body shape I broke into the happiest tears of my life. I could finally relate to an image of a woman’s body in the media.” Allison started blogging as an outlet for documenting her struggles with weight. “My early posts were laced with self-hate, but the more plus-size fashion blogs I read, the more I grew to love myself.” Her video series Inside the Dressing Room, in which she shares how clothes fit – or don’t fit – her size-24 form, has more than 22,000 subscribers, a fact she puts down to her body positivity.

A large part of the appeal of these blogs is that they provide a service, scouring stores and websites for clothes that fit and flatter. Few high-street stores or designer brands stock sizes larger than 16, even though that is the average British dress size – but these bloggers rate Simply Be, Asos Curve , River Island and Evans, which last month held its first runway show, featuring collaborations with Giles Deacon and Clements Ribeiro.

“If you want to recreate fashion from women’s magazines, shopping is really difficult,” says Rutter, whose dream is for Topshop to extend its sizing. “People think if you’re fat you shouldn’t want to look good because you ‘clearly’ don’t care.” Scroll through pictures on her and other plus-size blogs, and you quickly see these women reject the old rules, such as avoiding fitted shapes, graphic prints and horizontal lines. “When people read my blog it’s often the first time they’ve considered that they, as a fat woman, could wear trousers or a jumpsuit or clashing patterns,” she says.

But for all the positive feedback, there is also abuse. Allison has been told she is “ugly”, “disgusting” and “unhealthy”. “One [commenter] told me I should kill myself because I’m fat.” What keeps her blogging is her desire to prove the “fat-haters” wrong. More than that, she wants to eliminate the stigma associated with the word fat altogether.

The fashion industry is starting to pay attention. Such is their social media power that these bloggers are often signed up as consultants, designers and models. Allison reels off the brands for whom she consults, and Georgina Horne , 26, from London, of the blog Fuller Figure Fuller Bust , was flown to Milan to consult for the Italian brand Marina Rinaldi with other bloggers including Gregg.

“Social media has given plus-size women a voice we didn’t have before,” says Marie Denee, 32, of The Curvy Fashionista , who has more than 340,000 Facebook likes. “We’ve said, ‘I love showing off my legs, my curves, my arms and my belly,’ and now these options are starting to become available to us.”

But there is still a long way to go. The second Plus-Size Fashion Weekend was held in London earlier this year, but Nicolette Mason, 27, whose popular blognicolettemason.com led to a column in American Marie Claire, is worried that the often poor-quality clothes “prevent plus-size fashion being taking seriously”.

“All too often our culture tells us that the only people allowed to participate in fashion are thin, which is completely untrue,” adds Gregg. “Women can look great regardless of their weight, and they deserve to feel great too.”

Sara Dal Monte