At 80, Julia Child is still a champion of the good life. And with more than 40 years of fine dining under her belt--which fits quite trimly--she's a powerful argument for having your genoise and eating it too.

"I eat properly, and that makes a difference," Child says, as she helps herself to a slice of rich-looking coffee cake. Child, breakfasting before an appearance and book signing at Bullock's Sherman Oaks, is co-founder and honorary chairman of the American Institute of Wine & Food, which has taken on the challenge of promoting good nutrition.

Child is indignant about "this terrible era of fear of food." She believes in "enjoying food to the hilt." But that does not mean Lucullan overindulgence: "If I ate everything I wanted, I'd be Mrs. Six by Six. Now wouldn't that be something?" She chuckles heartily.

Her regime calls for eating a great variety of food, but in moderation, and balancing the intake with sensible exercise. "You don't have to have a diet meal every meal," she says. "You should look at your food intake over the week, leaving room for two or three binges."

Child, who is perturbed by repeated attacks on foods as unsafe, has not given up anything. Nor has she "lightened" French cuisine. "People have an erroneous idea of French food," she points out. "They think it's all butter and eggs and cream. But you don't have monstrously fat people in France like you see in the United States."

The French manage by eating well at meals and eliminating snacks. "If you don't have a really good meal, you're probably always hungry and snack because you're not satisfied," she says.

Child supports the USDA's new food pyramid with its wide base of grains and narrowed consumption of animal products. But she doesn't rule out animal fats or sugar. "There's nothing wrong with sugar," she says. "It's just empty calories." And she still condones sauteing with goose fat just as she did in 1961, when "Mastering the Art of French Cooking" hit the bookstores and upgraded American attitudes toward food.

What's more, Child personally likes "lots of red meat and gin." Her before-dinner drink of choice is a "reverse martini," a tall wine glass containing one part gin and seven parts Noilly Prat vermouth finished off with a dash of gin and a twist of lemon.

As the Bullock's crowd settles in, Child takes the stage with Eberhard Mueller, chef/owner of Opus and former chef at Le Bernardin in New York. Mueller conducts an interview with Child: "Have you seen anyone wittier and brighter at this age?" he asks the audience. Child turned 80 Aug. 15.

Child is not only witty and bright, she's also busy. She's involved in a new television series, "Cooking With Master Chefs," which starts shooting next February for airing in October 1993. Thirteen segments are already funded, and Child hopes to expand that to 26. The series will not be "for fluffies or beginners but for people who are very serious about cooking," she says. The chefs will do the teaching. "I'll be the Alistair Cooke," says Child, meaning she'll introduce the shows and supervise the tapings.

Child, who says she'll move permanently to California when she turns 86--she lives in Cambridge, Mass., most of the year, but has a home in Montecito--is as concerned about family values as the political candidates. "We must all make a tremendous effort to bring back the family table," she says. And, of course, those assembled around that table will eat nutritious, home-cooked meals rather than highly processed convenience foods.

To capitalize on the family values theme, Nancy Silverton and Mark Peel of Campanile and their daughter, Vanessa, 9, show the Bullock's audience how to prepare a "Family Celebration Brunch." Silverton demonstrates how to make Campanile's breakfast bran muffins; Peel and Vanessa produce omelets and a yogurt drink.

"If you know how to cook, it can be very, very fast," Child comments. She reminds her audience that she didn't know how to cook until after her marriage. (Child's husband Paul, a staunch helper throughout her career, is now 90 and lives in a nursing home near Boston.) "They often say he married me in spite of my terrible cooking," she laughs.

This recipe comes from "Resetting the American Table," a booklet of menus and recipes worked out by chefs and nutrition experts and published this year by the AIWF. For a copy, send a self-addressed, legal-size envelope with 52 cents worth of stamps to American Institute of Wine & Food, 1550 Bryant St., Suite 700, San Francisco 94103.

OPEN-FACED COUNTRY OMELET

1 plum tomato

Kosher salt

Ground black pepper

Olive oil