The star looked incredible in the daft comedy caper, but in a new interview she’s said that she felt “bloated”.
“When you have an idea in your head and then you see it come to life – that was just amazing,” she told Billboard.
“But I have to say, I think filming movies are fattening because you have craft services.
“You’re about to go on camera and you want to look your best, but then there’s a tower of donuts or something.
“I just remember putting on so much weight filming Spice World. I was so bloated by the end.”
Halliwell – now known personally as Geri Horner – also revealed the real reason Alan Cumming was involved.
The actor starred as Piers Cuthbertson-Smyth, alongside an unlikely cast that also included Richard E Grant, Roger Moore, Barry Humphries, Michael Barrymore, Richard Briers, Dminic West and Jennifer Saunders.
It turns out that Cumming was invited because Halliwell saw him in something very different indeed.
“I studied English literature and drama in college, and we went to the Hamlet at the Donmar Warehouse in London,” she recalled.
“As a student, I remember seeing Alan Cumming performing as Hamlet and I couldn’t believe that this man was spitting and crying and it was just amazing – the emotion he was delivering.
“When it came to Spice World, however many years later, it came to casting and we were going through pictures and I was like, ‘Let’s pick him, I saw him in Hamlet.’
“It was brilliant to have that caliber of actors to be in our funny movie.”
Halliwell has just released her new single Angels In Chains, in tribute to George Michael.
The track is out now, with proceeds to Childline.