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Three: We're Worried About Our Bodies Because We're Competing For You—and Against You
With more people both marrying later and getting divorced, it's a competitive environment for finding mates. And since this generation of women can support themselves, they're freer to pick a man for his cute butt. Lynne Luciano, Ph.D., who has researched body-image issues at California State University at Dominguez Hills, says women are tired of being objectified and have turned the tables on men. "They don't like a man to be overly vain," she says. "He shouldn't care too much about the way he looks, but on the other hand, he should look good."

At the same time, men are also shaping up because they're seeing that people who are fit are more successful at work. "Women are very good at using their looks for competition," Cash says. "So men think, 'I'd better clean up my act.'"