Here’s how Beyoncé slimmed down for THAT Met Gala dress

Beyoncé may have arrived over an hour late to last week's Met Gala in New York, but her incredible outfit more than made up for it.

The singer looked every bit the style icon in a beautiful sheer floor length Givenchy dress, but what had many people talking was her noticeably slimmer figure.

Though Bey still rocked her signature curves, the translucent fabric showed off every body part and it was clear she had lost a significant amount of weight since her last red carpet appearance.

Now, a source close to the mum-of-one has revealed Beyoncé's weight loss process, saying she turned to her favourite detox diet, the Master Cleanse ahead of this year's event.

The extreme diet, which requires followers to subsist mainly on a mixture of lemon juice, maple syrup, cayenne pepper and water, is definitely not a recommended diet plan but it is one Beyoncé has used more than once.

"Beyoncé's… been doing the Master Cleanse diet she's used before – she hasn't forgotten that it gets results when it matters. This time, she lost over a stone, 15lbs. in total. When Bey puts her mind to it, nothing can stop her," an insider revealed to Heat magazine.

The singer famously used the cleanse to help her to drop over 20lbs for her 2006 role in Dreamgirls, and it seems she has decided to revisit it nine years on.

Even when she's not on an extreme detox, Beyoncé is "almost always on some kind of diet," the source said. "She's been really strict for the last month – no carbs and mostly vegan with just the occasional protein cheat."

We agree Bey looked fabulous in that sheer dress, but we hope she's looking after her body too.