Vanity sizing is probably the reason your clothes don't fit.

The tears come thick and fast.

I am 13 or 14 years old, quietly sobbing while my mum stands just on the other side of the makeshift changing room, its fabric walls closing in around me. Mum's holding the curtains shut, giving me privacy as I change, asking me how the dress I was so excited to try on fits.

I say nothing as I wipe away the tears with the back on my hand, inspect the tag and conclude that I am much too big for a size 12. But the other dress I tried on, at a different store last week, was a 12, and it fit fine. It was actually rather... roomy. What changed?

It's a familiar scene for many young women. The dress in question could've been a pair of denim jeans or a miniskirt you've been eyeing for weeks. And the size tag could have said 4 or 20.

It doesn't matter what size is on the label, or what size you think you 'ought to' be. Because vanity sizing throws the entire game. 

Watch: How To Improve Your Daughter's Body Image: Post continues after video. 

Years ago, I didn't have the tools to understand how the often cruel world of fashion operates. It felt like something was wrong with my body. I was too cushy on the sides, much too big around the bust.

Now, in 2023, the term 'vanity sizing' has hit our vernacular, and has allowed people – including me – to have more literacy around online shopping, particularly when it comes to fast fashion and the vast discrepencies in sizing between high street stores.

Vanity sizing became a thing back in 1983, when the North American sizing guide was scrapped for a new version that reflected what the consumer wanted to buy — a larger cut with a smaller number on the label.

This move opened the door for brands to target their ideal shopper profile and create their own sizing strategy, cuts and styles.

Forty years and thousands of fashion labels later, vanity sizing has rendered size labels virtually pointless because today, clothing manufacturers may label clothes with sizes smaller than the actual cut of the garments.

So, a size 10 pair of jeans could easily fit a true size 12. And a dress labelled size 16 could have been made using measurements for a size 18 body.

Clothing brands' purpose in doing this is simple: downsized labels make customers feel good about themselves. 

Michelle Barrett has been obsessed with fashion for decades. After studying and graduating from The London College of Fashion in 2000, she pursued a career as a personal stylist where she has been helping curate women's wardrobes for 25 years.

And she's all too familiar with vanity sizing.

"It is deceiving the consumer into making a purchase in a smaller size. Brands are aware that women will feel better in a smaller size so they take advantage of that. The issue also causes confusion where a consumer might be one size in one store and something completely different in another," Barrett tells Mamamia.

A study from 2014, published in the Journal of Consumer Psychology, supports Barrett's arguments. The research found smaller size labels increased the self-esteem of their customers, and vanity sizing — as nefarious as its intentions might be — worked. Really, really well.

Imagine this scenario in the real world:

A woman who might have gained a few kilos over the past few years (COVID, the cost-of-living crisis and the general stress that comes along with life can do that to you). She's used to buying a size 10, but her go-to store's clothes no longer fit as well as they once did. Perhaps they're just a little snug in areas she's not all that comfortable with.

So she goes to another store and finds the size 10 options available to her there fit her perfectly – so there she will continue to shop.

And viola. Vanity sizing has made her feel both horrible about herself and quite amazing in the same breath.

Barrett says it impacts women of all ages, but especially those who suffer from body dysmorphia (which impacts about one to two per cent of the population).

"Vanity sizing would not exist if it were not for the simple fact that women struggle with body image issues," she explains.

"I regularly have women who come to me for help who have at least a mild case of body dysmorphia and it is always about them thinking they look bigger – therefore worse in their eyes. And it is simply not true. So many women put on a little weight after having children or during menopause and then struggle to find their style-happy place again, so they opt for easy – usually baggy – options."

So if you're struggling to find clothes that fit in the size you identify with, don't worry. So is everyone else. 

It's a deceptive marketing tactic in a world where brands are trying their hardest to have you prefer to shop with them.

"Vanity sizing is a symptom of this pressure to be young and skinny, when in fact, with the right knowledge, all women can look and feel amazing whichever size or age they are," says Barrett. 

"I would prefer to live in a world where deceiving women into purchasing clothes does not exist."

Feature Image: Supplied.