Elle Macpherson Decadent bra

Elle Macpherson's "Decadent" bra is carried at Selfridges in sizes 30DD to 36G. Photo courtesy of Selfridges.

We must, we must, we must increase our bust!

Well, turns out nature has taken that motto to heart. Selfridges of London has released new figures revealing that sales of bras with cup sizes D to G have risen by 50 percent year-after-year since 2005.

Ladies whose cups runneth over can find comfort in knowing that retailers are stocking larger sizes -- Selfridges even carries a K-cup bra by Fantasie that goes for £32 a pop (approx. $48). And it's not exactly your dainty Victoria's Secret number!

To wrap our heads around just exactly how ample a K-cup really is: The gigantic brassiere measures a whopping four feet around, with each cup coming in at one and half foot at its widest point, reports the Daily Telegraph.

Ladies who don't quite fill out a K can still find new offerings in the D to E range, for which Selfridges has increased its stock by 30 percent, including styles by Elle Macpherson (left) and Agent Provocateur.

The average bra size in the UK is now a 36D compared to a modest 34B only a decade ago. Selfridges lingerie buyer Helen Attwood attributed at least part of the phenomenon to our increasing waistlines.

"We are seeing more demand for the larger sizes and especially for fashionable, sexy bras in bigger sizes for younger women," Attwood told the Telegraph.

"We are in general getting heavier and therefore more women have larger busts, but it can even change depending on the time of the month."

Dr. Joanna Scurr, a biomechanics professor at the University of Portsmouth, isn't so sure. "Breasts are getting bigger but it's not just because we are getting heavier," she told the Telegraph.

According to Scurr's research, women's breast size has increased regardless of what the bathroom scale says. "We don't yet know the reason," explained Scurr, "but it has certainly made women much more aware of the need for correct support."

With K-size bras on the racks, she's not kidding!

For another trend in bras, read on but don't poke an eye out.