Whether or not Ronald Reagan is successful with his budget, no one can gainsay the impact of another sort of U.S. belt tightening, symbolized by his wife, Nancy, a size 6. At a time when gourmet cooking has become the national pastime, an estimated 20 percent of Americans, male and female, are overweight—and unhappy about it. Indeed there are weeks when the nonfiction bestseller list seems like a battle between the cookbooks and the diet books. But when author Chris Chase was approached to write a compendium of the wisdom du jour on both cuisine and weight reduction, she sputtered: "Why me?" The publisher, Coward McCann & Geoghegan, bumped the proffered advance to $150,000, and the result, The Great American Waistline: Putting It On and Taking It Off, is due out in April. A 40-ish New York actress and former model, Chase collaborated with Betty Ford and the late Rosalind Russell on their best-selling autobiographies. She is also known for her sardonic articles on show business, many of which were collected in her memoir, How to Be a Movie Star, or, A Terrible Beauty Is Born, if The Great American Waistline is a distinct departure, well, Chase is always game for new challenges. After a film appearance as a broadcaster in All That Jazz, she assumed the role in real life, first as a commentator on the CBS morning news last spring (she left after eight weeks when "things didn't work out"), and is currently on Ted Turner's Cable News Network.

She is not a fitness freak or disciplined in any way. In fact Chase says she would rather "eat chocolate and read crap than just about anything. "But then, she explains, "Guilt overcomes me, and I work like an s.o.b. "Between bouts of toil and indulgence, she took time out to chew the fat about America's passion for eating and dieting with Bonnie Johnson of PEOPLE.

When did the U.S. begin its love affair with food?

As Arthur Schlesinger Sr. pointed out, the very discovery of America was a byproduct of a dietary quest—Columbus was searching for spices. And what was our first national holiday? Thanksgiving—a feast. But the love for gourmet food that is evident today really began in the 1940s.

What caused this?

After the Depression people decided that they were never going to go without anymore and neither were their children. In addition, during World War II men went to Europe and tasted what James Beard calls "the real thing." Our country has a huge, relatively rich middle class. These were the people who started the craze for a poulet in every pot and a Cuisinart in every kitchen.

Every movement has its leaders. Who are the gurus of cuisine?

Julia Child was our first national food celebrity. She sold Americans on the notion that it's easy to cook fantastic French food. She was not a born cook. Her girlhood diet of choice had been jelly doughnuts, and she once set a stove on fire by roasting a duck without first putting it in a pan. Then in 1948 she went to live in Paris with her husband, and that's when she learned about fine food.

Is Child to blame for American gluttony?

She won't take any of the blame. She says that people have to be sensible and that she has to diet all the time or she'd weigh a ton. Yet I love it when she says, "I would rather have one spoonful of chocolate Malakoff than two bowls of Jell-O. Wouldn't you?"

Why did fast foods start in America?

Part of the reason is the automobile. You get in the car on Sunday with all the kids and what are you going to do? You're not going to take them to a French restaurant. Howard Johnson's is what I remember from my childhood. Those orange roofs and fried clams. A second factor is the working woman. Women come home at night and are too damn tired to cook.

Isn't it sort of embarrassing that our contribution to gastronomy is the Whopper?

No. Other countries love fast foods too. They've got them even in Paris where they're so snobby. French people say that they like to eat in American restaurants because they can have a meal and still get to a movie. If you eat in a good French restaurant, you are there for the duration.

Why are Americans obsessed with being thin?

Partly it's hero worship. Until quite recently, fat people were admired because it was assumed that they'd made enough money to eat a lot. Singer Lillian Russell, who caused palpitations in the hearts of men at the turn of the century, weighed nearly 200 pounds. But now the beautiful people are thin. Fat is no longer socially acceptable. We are an overweight nation yearning to breathe svelte. Fat is a health hazard. So we patronize diet doctors, sign up for exercise courses, bind our thighs in Saran Wrap and swallow amphetamines that we hope will suppress our desire for hot fudge.

Do the rich go about losing weight differently from the rest of us?

Rich people go to spas. They want someone to do it for them. I went to one in Florida where they give you things like egg-white omelets. It's a nasty little white thing that looks like a washcloth. It tastes like one too, but it has only 35 calories. I finally stopped eating the diet stuff. The doctor said it was okay. "You're not heavy," he told me. "You're just flabby."

Did you ever have a weight problem?

No. I was a skinny kid—like something out of Auschwitz. When I was 12 years old I was 5'5", which is what I am now, and I weighed 76 pounds. I looked like a toothbrush. I could have lived on rare steak, salad and a pear. I hated food. I hated sweets. I wish that were my problem now. I weigh 115—the fattest I've ever been.

Have you ever joined a gym?

I once joined a health club run by a man with big muscles and thick glasses. He had exercise machines and a swimming pool. He taught me to swim. I wore earplugs and eye goggles and a bathing cap and a gadget clamping my nose shut. I looked so bizarre people kept asking to take my picture. I don't go anymore. I don't like people seeing me in a bathing suit, and he wouldn't let me swim in a sweater and skirt.

So many of the so-called experts disagree about what's good and bad for you. What's your answer?

I suppose you should try the golden mean, to be moderate in everything. You should get some exercise. You should get some sleep and drink a lot of water. And nobody has a bad thing to say about vegetables, grains or fruits. But it's hard.

Has working on this book altered your life in any way?

No, only now I'm miserable. Every time I eat something that I really love—and everything I love, like chocolate, bacon, biscuits with butter, is bad for you—I suffer. The things I learned have ruined my life.