Several celebrities have posed naked for the Women's Health Body For Life campaign, including Made in Chelsea star Millie Mackintosh and former Pussycat Doll Kimberly Wyatt.
Also joining the campaign, which focuses beyond aesthetics to building a strong body, are heptathlete Louise Hazel, TV presenter Amanda Byram and personal trainer Tracy Anderson.
"I get comments on Twitter or in interviews with people asking, 'How do you deal with the fact people think you're too thin?'" Mackintosh said.
"I'm not too thin - I'm slim. I go to the gym to try to build muscle. I really try!"
She added: "My husband Steven [Professor Green] and I sometimes run or cycle together. 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!"
Wyatt said: "I know what it's like not to feel beautiful. 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."
Asked for her favourite body part, she replied: "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'."
Commonwealth gold medallist Hazel said: "I've competed since I was 10 and trained full-time - twice a day, six days a week - from age 18.
"Now I'm no longer competing, that's down to five times a week, once a day."
She continued: "I can probably go for about 10 days without exercise before I start going out of my mind. Life is different when not training at a competitive level - I used to burn food off immediately.
"Nowadays, I'm more conscious about what I'm putting in. But my body still has great muscle memory - if I don't train for a week, I can still snap back into shape. If you dedicate time to looking after your body, it will always pay you back."
Byram said: "A year or so before I turned 40, I thought, 'It's now or never'. I wanted to sculpt a strong body - one that would stay healthy and beautiful well into my 40s and beyond.
"If I was going to be naked, I wanted to feel at my very best, but normally, I'll weight train three times a week - it's the best for stripping fat.
"I don't have a strict routine. I like variety so I can wake up on a morning and think, 'What do I fancy doing today?' Listening to your body and what it really needs is one of the healthiest things you can do."
Anderson, who is Gwyneth Paltrow's personal trainer, said: "I train to feel healthy and in control, and that's liberating because I used to feel trapped by my body.
"At 19, I was training to be a professional dancer, but had piled on 35lb in a year. I'd hit the gym, go to Pilates, but it just made me stockier.
"I began working with a doctor who opened my eyes to the science of muscles - it took me five years of working on movement after movement before I had anything I dared call a method."
She added: "Now, I train as I teach, which usually means 90 minutes a day, six days a week - the mix of cardio and small-muscle work that's become my method. I've learnt so much about my body.
"I don't want the body of a 20-year-old, I just want to celebrate being the best me at this moment in time."
Read the full Body For Life interviews in the September Naked issue of Women's Health - on sale now. Also available as a digital edition.
Also joining the campaign, which focuses beyond aesthetics to building a strong body, are heptathlete Louise Hazel, TV presenter Amanda Byram and personal trainer Tracy Anderson.
© Women's Health/John Wright
Millie Mackintosh: "I'm not too thin - I'm slim"
"I get comments on Twitter or in interviews with people asking, 'How do you deal with the fact people think you're too thin?'" Mackintosh said.
"I'm not too thin - I'm slim. I go to the gym to try to build muscle. I really try!"
She added: "My husband Steven [Professor Green] and I sometimes run or cycle together. 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!"
© Women's Health/John Wright
Kimberly Wyatt: "I know what it's like not to feel beautiful"
Wyatt said: "I know what it's like not to feel beautiful. 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."
Asked for her favourite body part, she replied: "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'."
© Women's Health/John Wright
Louise Hazel: "I used to burn food off immediately"
Commonwealth gold medallist Hazel said: "I've competed since I was 10 and trained full-time - twice a day, six days a week - from age 18.
"Now I'm no longer competing, that's down to five times a week, once a day."
She continued: "I can probably go for about 10 days without exercise before I start going out of my mind. Life is different when not training at a competitive level - I used to burn food off immediately.
"Nowadays, I'm more conscious about what I'm putting in. But my body still has great muscle memory - if I don't train for a week, I can still snap back into shape. If you dedicate time to looking after your body, it will always pay you back."
© Women's Health/John Wright
Amanda Byram: "If I was going to be naked, I wanted to feel at my very best"
Byram said: "A year or so before I turned 40, I thought, 'It's now or never'. I wanted to sculpt a strong body - one that would stay healthy and beautiful well into my 40s and beyond.
"If I was going to be naked, I wanted to feel at my very best, but normally, I'll weight train three times a week - it's the best for stripping fat.
"I don't have a strict routine. I like variety so I can wake up on a morning and think, 'What do I fancy doing today?' Listening to your body and what it really needs is one of the healthiest things you can do."
© Women's Health/John Wright
Tracy Anderson: "I train to feel healthy and in control
Anderson, who is Gwyneth Paltrow's personal trainer, said: "I train to feel healthy and in control, and that's liberating because I used to feel trapped by my body.
"At 19, I was training to be a professional dancer, but had piled on 35lb in a year. I'd hit the gym, go to Pilates, but it just made me stockier.
"I began working with a doctor who opened my eyes to the science of muscles - it took me five years of working on movement after movement before I had anything I dared call a method."
© Women's Health/John Wright
She added: "Now, I train as I teach, which usually means 90 minutes a day, six days a week - the mix of cardio and small-muscle work that's become my method. I've learnt so much about my body.
"I don't want the body of a 20-year-old, I just want to celebrate being the best me at this moment in time."
Read the full Body For Life interviews in the September Naked issue of Women's Health - on sale now. Also available as a digital edition.
Read more: http://www.digitalspy.co.uk/showbiz/news/a587290/millie-mackintosh-and-kimberly-wyatt-go-naked-for-womens-health.html#~p1ODS7ZCjWGH1r#ixzz3PGmtMLb9
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