Women's size 10 waist has grown by 4 inches over past 40 years

London, April 10 (ANI): The average pair of women's trousers is four inches bigger than it was four decades ago, according to researchers.

They say a size 10 waist has grown from 24 inches back in 1975 to 28 inches now.

And bigger bellies are not responsible for it- it's all in the hips.

The researchers found the average hip size has grown by three inches over the same period, the Daily Mail reported.

The findings mean women who are a size 10 now would have had to buy size 14 trousers in 1975. And those who were size 14 then would be an unflattering size 18 now.

According to fashion experts, clothes makers have stretched sizes out over the past four decades, to hide the fact women are slowly getting bigger and bigger.

Gemma Seager, from fashion blog Retro Chick described the trend as 'vanity sizing'.

"There's definitely an element of trying to flatter women who are going to be delighted if they fit into a smaller dress," she told the Daily Express.

"If you look back you can see a gradual change decade by decade, so someone who wears a modern Size 10 would be a Size 12 from the Eighties, a 14 in the Seventies and a 16 to 18 in vintage clothing from the Fifties. Retailers know it's a bonus if a woman finds an item she likes and it's a smaller size than she generally wears," she said.

Men aren't affected by 'vanity sizing' because their trousers are measured in inches.

But it's an issue that gives women across the country a headache every time they hit the shops. Because not only have clothes sizes changed over the decades - they vary from shop to shop.

Seager claimed the constantly changing sizes makes it hard for women to figure out what size to buy - particularly when a size 10 in one shop is a size 12 in another.

Her concerns prompted her to launch the Campaign for Clearer Clothing Sizes, which calls on retailers to put exact measurements on labels and publish size charts online.

"Most women don't care that much what size is on the label as long as the garment fits them well," she said. (ANI)