At size 16-18 (on bad days a 20), I am what some people describe as a "plus-size" woman. I often wonder how to describe my body to strangers/blind dates/online friends. Within the lexicon of large there are the euphemistic (and frankly disingenuous) terms like plus-size, curvy, voluptuous, full-figured, big boned and heavy set, which kind of conjure up images of either someone teeny tiny like J-Lo who happens to have breasts and a bottom (I have witnessed her close up and can verify she is bird-like) or a maximum size 16 like Crystal Renn (above) – ie on the hefty side of slim. American Apparel were recently recruiting for "plus-size models". What they meant by that was US size 12-14 (UK 16-18). But of course, what all that these words signify to those who use them to describe ourselves is someone size 18 or 20 plus – the size of Dawn French before she dieted.

Beth Ditto on the catwalk with Jean-Paul Gaultier. Photograph: Dominique Charriau/WireImage

Then there are the honest terms: overweight, large, big, fat. No nibbling at the truth – they mean what they say. In fact, there has been something of a reclamation of the word "fat" in recent years, with French calling her autobiography Dear Fatty and Beth Ditto coining the zeitgeist term "fatshionista". There's a lot to be said for the word "fat" – it hits home hard. Lets face it: "plus-size is a feminist issue" wouldn't really have had the same impact. If it's good enough for Susie Orbach and Beth Ditto, its good enough for me.

Sometimes, when I'm feeling playful and camp, I refer to myself as a "larger lady" or a "bigger gal". But on depressed days I seize upon the label "clinically obese" – muttered angrily to anyone who'll listen.

You may wonder why I'm pontificating upon this spectrum of heavyweight signifiers. Its simple, really. Like me, the average size of a UK female is now a 16. One in four is a size 18 and it's predicted that, by 2030, 40% of us will be obese. Of course, in health terms that's nothing to celebrate – in fact it's cause for grave concern. But obesity is a complex issue; mine, for example, is caused by the medication I have to take. It alters my metabolism, bloats my stomach to pregnant proportions, and neither diet nor exercise make a jot of difference to my figure.

So some of us have to try to find acceptance and the positives in our corpulent bodies – a difficult one. One of the escape routes is obviously fashion. I love perusing clothes – in catwalk shots, on the internet and in shops. I love the ideas and the imagination and the fantasy of it. But because I'm fat, the reality under the harsh lights of the changing room can be uniquely depressing.

In the fashion world, things for larger women are on the up: Italian Vogue featuring three plus size models on its cover earlier this year; Marc Jacobs announcing he is doing a plus-size range; current and forthcoming collaborations such as Zandra Rhodes for Simply Be.

A sneak preview from the Asos Curve AW 2012 range (Click here for more). Photograph: Asos.com

But at the lower end of the spectrum, the current state of affairs is problematic. I'm based in Shropshire, and if you're size 16 or over and live in the provinces, there's one place you end up heading and that is Evans. I'm hugely excited about the prospect of Clements Ribeiro taking the reins there in spring 2012 – I used to buy their clothes in the late 90s and early noughties when I was a slim young thing. Because Evans pre-Clements has been frankly appalling. I've bought the occasional piece in there (a pair of boyfriend jeans last summer), but generally the choice is drab, dingy and about three years out of date.

Another shop in need of a drastic overhaul is Zara. I adore window shopping outside it – the outrageously good approximations of Prada, Marni, Jil Sander and co at affordable prices are truly laudable. The sizing, however, is not. For the fat/obese/plus-size, Zara is a theatre of cruelty. A Zara XL is meant to fit a UK 16, but in my opinion a 14 would be lucky to get it over her head. When are they going to cater for us chubbies? They're missing out on a huge (sorry!) demographic, and they don't seem to care. Perhaps all Spanish women are built like Penelope Cruz, but somehow I suspect not.

But it's not all doom and gloom. One cause for celebration in recent years has been the arrival of Asos's Curve. At last, a fatties range that's bang on trend: Peter Pan collars, pleated skirts, pussy-bow blouses, palazzo pants. It really is a fun place to shop and in no way a plus-size ghetto. It's probably really geared towards trendy teens and 20s but I sometimes shop there and I'm knocking on 40. What I want to know is, why can't Topshop and Zara and everyone on the high street be as inclusive and vibrant as Asos? I, for one, would be tearing down their doors.

• If you have suggestions for good high-street options for plus-size women, let us know below