Valerie Harper used to be, as she put it, "the crown princess of chubby." When she first sashayed into hearts of television viewers as Mary Tyler Moore's upstairs neighbor, she was the All-American schlump, the "she's so pretty, too bad she can't lose some weight" working girl, the patron saint of imperfect. In her layered outfits, identifiable to those who identified with her as the kind of clothes you wear to hide that somewhat ample derriere, she made despair seem almost glamorous.

Now she's thin. But has she sold out, abandoning the millions who looked to her as an antidote to thinness-worship, a role model against the real models?

"I don't think so," she laughed. ". . . I used to be a ballet dancer, but I could never get rid of these," she said hitting her thighs, "even when I was thin." But now she has.

The secret: "Balance." Three kinds of exercise: running (three or four miles every other day), yoga stretching (a half-hour to an hour a day) and weight lifting (every other day).

"Not the stuff we did in gym class, jumping jacks. And not necessarily male exercises. I don't lift the heavies, I have three- or five-pound barbells. It's been so good for the old bust line. If women are large they can firm it up; if they're small they can build it up . . . That's where it's going to be at for women. This soft, no definition thing is going to start going out as a symbol of beauty. The beauty of fitness, of muscle definition, firmness, is coming in. No more the soft Marilyn Monroe look, or the pampered darlings like the ladies at the turn of the century who died from wearing corsets. Look at fashion and you'll see a political statement . . . . Sorry if I'm sounding radical."

She was in town to accept an award last night from the National Commission on Working Women, a privately funded organization for the "approximate 80 percent of the women in the work force who are concentrated in clerical, service, sales, factory and plant jobs." She, as well as actresses Esther Rolle ("Good Times") and Linda Lavin ("Alice") were honored for their contributions to prime-time television programming dealing with issues of special concern to working women. In Harper's case, she won for her portrayal of a factory worker who is the victim of sexual harassment in last season's "Fun and Games."

At 40, she's glowing with good health and firmness, happy about work and love, and volubly involved with concerns about women, the world and politics. She is not as thin as she was in one of her recent movies, "Chapter Two," in which she played a woman "trying to look like an Italian Vogue magazine and failing." She was, she said, too thin in that.

This week she returned from an 11-day trip to Somalia organized by the Hunger Project, an offshoot of Werner Erhard's est system, of which she is a graduate. The Hunger Project, she says almost offhandedly, is "committed to ending hunger by the turn of the century." It functions as a "free p.r. firm for the voiceless. We don't sent one grain of rice, but we support those who are."

The first thing she noticed in Somalia, where hundreds of thousands of people are starving, caught in a war between Ethiopia and Somalia as well as a five-year drought, is that 90 percent of the people she saw in refugee camps were women or children.

"Starvation is inextricably tied to the lack of women's rights in the world," she said. "The thing that's really going to be the revolutionary thing in the 20th century is women coming into their own, truly as equals, not as some special interest group."

It's all a part of a package, as she sees it -- the new, muscled, self-controlled bodies, women taking responsibility for ending hunger, confronting sexual harassment with a clear-eyed dismissal born of self-confidence.

"I'm not saying there's a conspiracy against women. That's just what's being manifested out of women not being really people. And that's been part of our institutions for centuries, from Aristotle to Thomas Aquinas to rape laws today. In California we just removed a thing from the statute that required resistance for rape to be a crime. And anal or oral sodomy was not considered rape. If that's not legislation against the vagina, I don't know what is.

"Men are not the enemy. It's that we've all adhered to a lie, the lie that women are less."

Her own relationship with Tony Cacciotti, who was her fitness coach, is "beautiful." They have formed a production company called, "tal," which stands for "together at last."

She is optimistic about the incoming Reagan administration, with typical est-ian enthusiasm ready to communicate with them and "enroll Reagan in ending hunger and working on the status of women.

"We can make a lot of pronouncements about 'Oh my God, it's going to be terrible,' but that doesn't serve anything . . . . We have to look at why it happened -- it's because of fear. Fear of scarcity; inflation scares the hell out of everybody. Let's not count anybody out even Jerry Falwell or Vinigrie [Richard Viguerie] -- is that his name? Or that Heritage group, it's no use saying oh, they're Nazis; you have to look beneath to see their humanness, to see what they are afraid of. We've got to keep including."

Reagan's opposition to the ERA could be the impetus needed to mobilize the pro-ERA forces, she said. Just as organized opposition to Anita Bryant strengthened gay power.

Harper was told that while she was in Somalia, Anita Bryant said that her atitudes had mellowed a little and she now believed in "live and let live." hHarper jumped off the hotel room bed in excitement. "That's what I'm talking about!" she said. "My God! That's fantastic."

Local Winners of the 1980 Women at Work Broadcast Award include: 1first Place, television: "Everywoman: Just Ask Phyllis Martin," WDVM.Producer: Debra Goldberg, reporter: Maureen Bunyan. Third place, public affairs: "Social Security: Time for an Overhaul?", WETA. Producer: Ricki Green, reporter: Andrea Roane. Honorable mention, public affairs: "What Does Your Mom Do?", WJLA-TV for the Eighth Decade Consortium. Producer, Kathleen Cunningham. Honorable mention, portraits: "longshots: Anne Butler," WJLA. Producers: Ed Turney, Paul Fine, Holly Fine. Special Citation, entertainment: "International Women's Day Concert," National Public Radio. Producer, reporter: Karen Hushagen. Honorable mention, public affairs: "Academy Women: Fighting an Uphill Battle," Associated Press Radio Network. Producer/reporter: Patti Berman. Special Citation, news feature: "Chicken Farm Strike in Laurel, Mississippi," National Public Radio, producer/reporter: David Molpus.