The teenagers staring out of the pages of Seventeen Magazine have flawless skin, perfect teeth and figures even Barbie would envy. Many young girls have adopted dangerous diets and tortuous beauty regimens in an attempt to emulate the beautiful models, an impossible task. Most magazines, including Seventeen, use photo editing software to make models thinner, taller and blemish-free, an illusion that fools most readers.

But activists have been working to persuade magazines to use unaltered photos, and this month Seventeen agreed.

Ann Shoket, editor-in-chief of Seventeen Magazine, announced the publication would start promoting healthy habits, but denied accusations that its editors used Photoshop to edit their models' faces and figures. Activists who oppose altering models' photos viewed Shoket's statement as admission that girls featured in the magazine are touched up, But they applauded the magazine's new commitment to show all kinds of beauty.

"We want every girl to stop obsessing about what her body looks like, and start appreciating it for what it can do!" Shoket said in the most recent edition of Seventeen.

Julia Blum, a 14-year-old ballet dancer from Maine, led the campaign to stop photo editing young models. With the help of SPARK Summit, an activist organization that promotes healthy images of women in the media and opposes sexual objectification, and a petition containing 84,000 signatures, Blum persuaded the magazine to agree to limit editing photos of young girls. If editors do use body touch-ups, they will post before and after pictures to the magazine's Tumblr website.

"No longer will Seventeen Magazine show those images that we all find so disturbing: miniaturized waists, enlarged heads, and, of course, picture-perfect everything," Ben Ubiñas, a blogger for SPARK, said in a post on the group's website, "Images that hurt us all, girls by being encouraged to look like the impossible, boys by being made to expect the impossible."

Seventeen also created its own campaign - "body peace treaty" - to encourage its readers to love their bodies and treat them with care. On the magazine's website, editors posted 17 vows readers can take to encourage them to live better, healthier, and happier.

Seventeen is not the only fashion magazine that alters model photos. But, Seventeen targets an age group prone to the influence of eating disorders and depression that stems from dissatisfaction with their bodies.

"As long as we don't reconfigure the way girls see themselves on TV, in movies, on billboards, in fashion magazines, and in music videos, even our smartest teenagers will continue to believe the media lie that all their worth is in their fastidious attention to the superficial and transitory," said Chelsea Carmona, an opinion columnist for the Christian Science Monitor.

Carmona, like many other supporters of the measures, hope to see other magazines and various forms of media follow Seventeen's lead.

Audrey Brashich, a former teen model and editor of the now defunct teen magazine YM, said the Seventeen pledge has far more potential for immediate, tangible changes in the minds of girls than a recent vow from Vogue editors around the world to ban models under 16 or those of any age with visible signs of eating disorders.

SPARK plans to take on more media-driven photo editing in the future. They already announced their next target - Teen Vogue. For now, the group is encouraged by the efforts of Seventeen.

"Seventeen listened!," Blum said in on the petition website, "This is a huge victory, and I'm so unbelievably happy. We are sparking a change!"

The Associated Press contributed to this report.