As well as Millie, former Pussycat Doll Kimberly Wyatt and trainer-to-the-stars Tracy Anderson also posed in the nude for the series of stunning black and white photographs.
The Body For Life campaign embodies the Women’s Health ethos that a healthy body isn’t just about pure aesthetics - it's about building a strong body that will protect you against illness and injury and keep you feeling (and inevitably looking) great for years to come.
Millie Mackintosh told the magazine: "I get comments on Twitter or in interviews with people asking, ‘How do you deal with the fact people think you’re too thin?’ I’m not too thin – I’m slim. I go to the gym to try to build muscle. I really try!
She also revealed that she relies on the support of her hubby Professor Green to achieve her Body For Life.
“My husband Steven and I sometimes run or cycle together," she said. "But he’s also good at reminding me I need to rest. I don’t want to be skinny and I don’t want a six-pack – I just want health… and some definition!”
Dancer and singer Kimberly Wyatt, who also posed naked for one of the shots, says she struggled with the pressures of being a popstar to maintain a healthy body balance.
“I know what it’s like not to feel beautiful," she said. "I’ve had the executive at the record label suggest I’d be better if I looked like an anorexic alien.
"But I’ve always resisted the pressure to stick my fingers down my throat. I think I’m lucky my training has never just been about my body – it was driven for my love of dance.”
As for her favourite body part, Kimberley says, “Shoulders and back. Ballet is brilliant for muscles in these areas, so when I see mine in the mirror, I’m like, ‘Yeah, I worked my ass off my entire life for those.’”
Read the full Body For Life interviews in the September Naked issue of Women’s Health – on sale Wednesday 30 July. Also available as a digital edition. www.womenshealthmag.co.uk