Ms Fink said body image concerns were not limited to girls, but research showed they viewed their bodies more critically than boys.
"How girls and young women feel about their bodies can have a pervasive effect on their mental well-being and enjoyment of life and can lead to depression and social isolation. Concerns about body image can prevent young women from participating in a range of physical and social activities," Ms Fink said.
She said messages throughout popular culture encouraged young women to "look a certain way, be a certain weight and do certain things".
"A girl's value as a person is so much more than how she looks but the messaging we constantly receive from media, peer groups and even, in some cases, from our families serves to reinforce a self-critiquing mindset in young women.
"Traditional self-esteem promotions tend to be appearance focused, for example how to look slimmer by dressing for your body shape. This suggests body image has a disproportionately greater value than other aspects of a young woman. We want to move away from that approach and look to value a young woman's skills, talents and personality traits."
Teen believes balance is best
Brittany Cairns says any girl going on a diet should stop being stupid.
Teenager Brittany Cairns has a simple message for young Kiwi women: what you're born with is what you've got - so make the best of it.
The 16-year-old said: "I am happy with my body. I mean, I have those days where I wish I didn't have the curves I do or that I could eat a tonne of M&Ms and it have no effect but doesn't everyone?
"I think I have a healthy body image. I have curves but I maintain them, and I also love to eat fatty foods every so often."
Brittany said she didn't feel the need to diet and anyone who thinks they should was being stupid.
"A good balance between healthy food and non-healthy food and a good amount of exercise is better than starving yourself or going crazy at the gym. If any of my friends told me they were thinking of dieting I would make them eat pies every day. I love my friends for who they are not the size of their jeans."
Brittany said she thought Kiwi girls worried about body image too much.
"There is so much social media and society printing 'perfect' looking girls into mags and putting 'perfect' girls on TV and we think 'I have to look like that' - as a matter of fact you don't. People are perfect in different ways, it's just not what you see in Home and Away or the magazines.
"The media make these stars something to aspire to be like and that's what puts the pressure on young girls as they think they have to be the same."
Take part
The campaign is open to all young New Zealand women over 13 years of age and ends on July 31.
For more information, visit www.facebook.com/pages/YWCA-of-Aotearoa-New-Zealand/109017730239