A young woman's development focuses a lot on relationships with her peers, men and and her parents, Bradshaw said. To maintain those relationships she submits to an ideal of physical appearance, she said.
That ideal is drawn from television, movies, and magazines, where the images of women are touched up, enhanced by computers, or even assembled from different models, she said.
"It's not reality. It doesn't represent most women," Bradshaw said. "Most women's bodies are not built like that."
Jan Nachamkin, 26, a walk participant, said she wants to see women better represented in toys like Barbie, who would have to be more than seven feet tall for her proportions if she was real.
"Women need to start accepting themselves for what they are and to be happy with themselves," said Jessica Almony, 21, another walker.
Beth Stephens, 19, said women's magazines should "get real and show teenagers what's real instead of some false image."
Bradshaw said men will soon experience the same problem."All you have to do is pick up any magazine and you see images of perfectly built men," she said.
She said the message starts to hit children in middle school, when their bodies are going through many changes. Parents need to downplay the importance of an ideal weight and appearance, she said.
"It's what's inside that counts, talent and what they can do," she said.
Bradshaw said her research shows that the average model today is 23 percent thinner than the average women. A generation ago models were 8 percent thinner.
She said 70 percent of young women are disatisfied with their bodies by the age of 17, and 75 percent of women between 18 and 35 believe they are fat. She said 80 percent of 4th-grade girls are dieting.