From PEOPLE Magazine Click to enlarge
As the founder of the 20,000-member youth organization Earth 2000, Danny Seo, 20, is a staunch believer that when things need changing, you change them. Sometimes that means forcing a development company to rethink its plans to raze a forest; sometimes it means pushing for legislation to let students refuse to dissect animals in class. And sometimes it means taking a hard look in the mirror. "I had my first picture in Newsweek when I was 17," recalls Seo, who was interviewed for a story on teen vegetarians. "After I saw it, I changed my clothes, joined a gym and got a haircut."

The makeover was successful. "There's no doubt that Danny Seo is an eye-catcher," says actress and animal rights activist Gretchen Wyler. "And his beauty goes all the way to his heart."

Yet even with an exercise regimen that includes a daily gym workout, the 5'10" Seo, who lives with his parents in Reading, Pa., is often mistaken for a schoolboy. He gets carded for R-rated movies, and last year a woman on a Washington subway asked him which junior high he attended. "People always think I'm younger than I am," complains Seo, who has decided to skip college to pursue his environmental efforts.

With a mind-boggling schedule of fund-raising, congressional lobbying and travel to high schools around the U.S. to teach young people how to get involved (his 1997 guide, Generation React: Activism for Beginners, is now in its second printing, and he's working on a second book), Seo is obviously focusing on others. "He doesn't fuss a lot about the way he looks," says his friend Melissa Hicks, a geology student. "I've never seen him stare at himself in a mirror." Still, he tends his skin with all-natural products like Kiehl's astringent and Aveda hydrating lotion. And to keep his thick, black hair shiny and in place, he massages body lotion in it as well. "I tend to find many uses for one product," he says. "I'm a minimalist."

Except when it comes to food. In an ongoing battle to keep weight on, Seo tries to eat eight meals a day. But between his hectic calendar and an ethical aversion to eating any meat or animal products, it isn't always easy. "My worst feature," he says, "is my raging metabolism."