Slipping easily into a tiny sample-size dress designed by former bandmate Victoria Beckham, Melanie Brown lets out a cheer. “Woohoo!” she grins. “I didn’t have to squeeze into it, there was no huffing and puffing, and I didn’t have to put on a gazillion pairs of Spanx underneath. I don’t even have to constantly suck my stomach in.”

Just six months since giving birth to her third daughter, Madison, having spent 20 weeks on Jenny Craig, Mel has lost a whopping 15kg to reach her goal weight of 60kg. But it’s not just that she’s got her pre-baby body back. In fact, with her minuscule waist and toned arms, she looks as fit and fabulous as she did in her days as the wildest member of the world’s most famous girl band.

If there were a Spice Girls reunion in the next few months, as Mel has hinted, she could be back on stage in those same old racy outfits. No mean feat considering she was just 21 when the group achieved global fame – and these days she’s a 36-year-old mum-of-three. “It’s crazy,” Mel agrees.

“I’m not so keen on the platform heels, hot pants and little bra tops these days. And I’ve got extra tattoos, different hair, a bigger diamond on my hand and I’m a bit more mature in the face. But otherwise, I’m still the same girl from 15 years ago. The six-pack is pack!”

Read more about Mel's transformation plus see all of the before and after pictures in this week's Woman's Day on sale Monday February 27, 2012.