The American palate is an anomaly. U.S. consumers want their burgers and pizza, but they also can’t do without their imported cheese, organic baby greens, bottled water and fancy coffee. Approximately 20% of Americans eat three or more meals per week at fast food joints, but 15% drink a cup of specialty coffee every day. And if the distinction between coffee from Starbucks and fast food sounds like a false one, that’s simply a measure of how accustomed we have become to upscale eating. A measure: In 1990, there were 84 Starbucks outlets in America. In 2000, there were more than 3,000. And Starbucks, of course, has inspired numerous spin-offs: Today, there are more than 21,000 specialty coffee houses operating in the U.S.

But if you look back 20 years or more, you get a very different picture of the American diet. Supermarkets were stocked with green cans and plasticized orange squares that signaled the idea of cheese; bitter instant crystals that passed for coffee; tasteless iceberg lettuce that anchored salads; and Jello, Spam, and Tang that represented the futuristic ultimate in culinary convenience. Today, consumers willingly eat what they would have balked at back then — sushi, tofu, salsa –and they stock their kitchens with ingredients that were virtually unheard of just a few years ago — extra virgin olive oil, balsamic vinegar, goat cheese, sun-dried tomatoes and, of course, exotic greens such as arugula.

In his best-selling book Fast Food Nation: The Dark Side of the All-American Meal, Eric Schlosser showed us an America growing morbidly obese on the cheap, easy food perfected by billion-dollar chains such as McDonald’s, Wendy’s, and Burger King. In The United States of Arugula: How We Became a Gourmet Nation, David Kamp fills in the rest of the story, describing how, at precisely the moment that fast food became a fixture of American culture, an ideal of fine American dining also emerged. We may be fat, and we may be addicted to sugar, salt, and convenience, but we also have good taste. We adore our Big Macs and fries, but we also swear by our cappuccinos and croissants.

In highly readable, often humorous prose, Kamp describes how, during the 1940s and 1950s, an egalitarian America suspicious of anything — even food — that smacked of elitism began to accept the idea that it wasn’t necessarily un-American to put great stock in really good food. Beginning his chronicle in 1939, when the now-legendary James Beard took on the task of defining a distinctively American cuisine, Kamp explains how World War II brought the rich flavors and refined pleasures of French cooking to the U.S. He shows how refugee French cooks flocked to New York, where they quickly set up immensely popular restaurants, and he shows, too, how Americans stationed overseas — among them future chefs and food critics — were introduced to new and inspiring culinary worlds. After the French infusion at home and soldiers’ experiences eating in Europe, Kamp observes, the uninitiated American palate, used to bland, unimaginative fare, would never be the same.

Having set the stage — or, more correctly, the table — Kamp provides a mouthwatering tour of America’s culinary coming of age. He walks the reader through the 1960s-era of Americanized Escoffier-style cuisine, brought to us by the redoubtable Julia Child, whose outsized personality and cannily adapted recipes — custom fitted to the American market, with its limited range of fresh and exotic ingredients — brought French cooking into kitchens across the country. He leads us through the post-1960s countercultural rediscovery of local, seasonal ingredients, anchored by Alice Waters’ Berkeley-based restaurant Chez Panisse. He explains how delicacies such as grass-fed beef, free-range chicken, baby greens and goat cheese found their pricey market niches. And he charts the rise, during the 1980s and ’90s, of a genuinely gourmet pop culture exemplified by specialty shops such as Manhattan’s Dean & DeLuca; celebrity chefs such as Wolfgang Puck and Emeril Lagasse; high-end, socially conscious brands such as Starbucks coffee and Ben & Jerry’s ice cream; Zagat restaurant guides; the Food Channel, and the ever-expanding Martha Stewart empire.

Kamp’s narrative of the American palate is self-consciously optimistic — “Food is one area of American life where things continue to improve,” he notes — and as such his book counters not only the depressing culinary picture painted by Schlosser, but also stands in marked contrast to the growing number of alarmist narratives that surround American consumer culture today. Think Morgan Spurlock’s fulsome documentary Super Size Me, or, on a different note, Al Gore’s admonitory An Inconvenient Truth.

Celestial Seasonings, Peet’s and Moosewood

Much of Kamp’s optimism stems from the unspoken libertarianism of the book, the sense that the market can be trusted to self-correct — so much so that it can even be trusted to correct failures of taste. Americans may have been historically known for their poor cooking and worse taste, Kamp convincingly argues, but all they needed to mend their gustatory ways was the opportunity to eat good food. The revolution of the American palate over the past half century is, for Kamp, also a triumph of the American market.

The United States of Arugula is thus more than a history of American eating habits. It is also a compendium of American cuisine’s greatest economic coups — its bestselling cookbooks; its fabulously successful restaurants, and its creation of entire new markets for farmers, retailers, and chefs. Kamp regales us with the stories behind Celestial Seasonings herbal tea, Peet’s coffee, Niman Ranch beef, Williams-Sonoma kitchen equipment, the Cuisinart food processor, the Moosewood Cookbook and San Francisco’s Greens restaurant. He also treats us to a broader tale of economic mainstreaming, one in which the gradual sophistication of the American palate took place by way of an enormous expansion of the mass market. In typical American fashion, exclusive tastes are becoming universal. The wide availability of our gourmet necessities — sushi in the supermarket, espresso at Dunkin’ Donuts — ensures that the project of refining our national palate remains a populist one.

Pizza is perhaps the single most telling example of this democratizing mode of sophistication. In 1939, Kamp notes, a New York Times columnist had to explain to readers not only what pizza is, but how to pronounce the word. Today, pizza is the ultimate American crossover food, available as both a greasy, cheesy fast food — delivered to our doors, some vendors promise, in 30 minutes or it’s free — and as a consummate gourmet experience. When Wolfgang Puck makes a pizza, it becomes synonymous with fine dining. At Spago, Puck’s signature L.A.-based restaurant, pizza is topped with smoked salmon, morel mushrooms and caviar; it may be served with white wine, consumed by candlelight.

Celebrating the innovation, variety and increasing affordability of upscale American food, Kamp’s book forms a welcome complement to another important recent work on American food ways, Michael Pollan’s The Omnivore’s Dilemma. Pollan is deeply concerned with the human and environmental costs of America’s eating patterns: Focused on the supply side, he tells a largely depressing story of a nation dominated by money-hungry corporations bent on selling food whose nutritional quality and ecological sustainability are far less important than its profitability. Pollan romanticizes small farmers and fresh ingredients, but doesn’t see many Americans able or willing to rearrange their diets in personally nourishing, environmentally sound ways.

By contrast, Kamp concentrates on how innovative entrepreneurs can alter both the supply side and the market itself. Chefs eager for baby greens, organic chicken and even zucchini flowers have taught farmers that these things are valued and valuable; farmers, in turn, have re-oriented their enterprises to supply a demand that has now expanded beyond the restaurant to the supermarket. As availability shifts, people eat differently; cooking shows anchored by celebrities such as Rachael Ray and Emeril Lagasse help translate gourmet cooking with fine, fresh ingredients into a lifestyle choice that makes sense for even the busiest, most budget-conscious households. Meanwhile, Rick Bayless, world famous for his take on Mexican food, has partnered with Burger King to develop and promote a line of low-fat grilled chicken sandwiches. Alice Waters has launched a campaign for better quality school lunches. Wal-Mart has begun selling organic food. And even McDonald’s — chastened, perhaps, by the drubbing Morgan Spurlock delivered in his 2004 film — now proudly announces that it uses up to 16 kinds of lettuce in its salads.

There are purists in the gourmet world who deplore the popularization of fine American dining, who criticize the Emerils of food TV for working to demystify quality cooking and who are positively offended by the fast food establishment’s attempts to take advantage of the gourmet mystique. But there are others who see these developments as part of American culinary culture’s natural and inevitable progression. Indeed, for Kamp, McDonald’s may well be the future of a truly gourmet American nation. Kamp’s concluding vision is of a McDonald’s that works with farmers the way top chefs currently do, sourcing quality ingredients locally and guaranteeing that even America’s fast food is as fresh, as healthy and as sustainable as possible. A McDonald’s that could do that, that would do that, Kamp argues, is a McDonald’s that would change the American diet for good. This may be a pipe dream — but it may also be the beginning of a singularly appetizing marketing plan.