Only 3 years old, Leon Gustavo Davila Hinojosa is still learning to speak Spanish. But the precocious youngster already knows a bit of Japanese: "Maruchan."

That's a brand of instant ramen noodles that to him means lunch. Leon's grandmother stocks them in her tiny grocery store in this hamlet 40 miles southwest of the capital. The preschooler prefers his shrimp-flavor ramen with a dollop of liquid heat.

"With salsa!" he said exuberantly at the mention of his favorite noodle soup.

Through the centuries, Moorish spices, French pastries and Spanish citrus have left lasting impressions on Mexico's cuisine. Now Japanese fast-food noodles, first imported here in the 1980s, are filling pantries across the country.

Time-pressed schoolchildren, construction crews and office workers have helped turn Mexicans into Latin America's largest per-capita consumers of instant ramen. Diners here slurped down 1 billion servings last year, up threefold since 1999, according to a Japanese noodle association.

Urban convenience stores do a brisk trade selling ramen preparada, providing customers with hot water, plastic forks and packets of salsa to prepare their lunches on the spot.

People in the countryside have developed a taste for it too. As part of a food assistance program, the Mexican government distributes ramen to commissaries in some of the most remote pockets of the country, where it is supplanting rice and beans on many tables.

The product is so pervasive that a national newspaper recently dubbed Mexico "Maruchan Nation."

Purveyors say you don't have to strain your noodle to figure out why. Nearly 60 percent of Mexico's workforce earns less than $13 a day. Instant ramen is a hot meal that fills stomachs, typically for less than 40 cents a serving. The product doesn't need refrigeration and it's so easy to make that some here call it sopa para flojos, or "lazy people's soup."

Sold here mainly in insulated, disposable containers that look like foam coffee cups, instant ramen starts as a clot of precooked dried noodles topped with seasoning and a few dehydrated vegetables. Boiling water turns the lump into tender strands of pasta in broth, ready to eat in three minutes.

That's a profane act for some Mexicans whose relationship with food is so sacred that their ancestors believed that humankind descended from corn.

Food here is history. It is religion. It is patrimony. Ask anyone who has savored such delights as chiles en nogada, poblano chilies stuffed with spiced pork and topped with creamy walnut sauce and pomegranate seeds to replicate the green, white and red of the Mexican flag.

It's also passion. In Laura Esquivel's popular novel "Like Water for Chocolate," the sensuous alchemy of Mexican cooking unleashes a family's ravenous desires.

Small wonder that defenders of the nation's cuisine, such as Gloria Lopez Morales, an official with Mexico's National Council for Culture and Arts, are appalled that Mexican palates have been seduced by this ramen import.

Lopez is leading an effort to have UNESCO, the United Nations Educational, Scientific and Cultural Organization, recognize Mexican food as a "patrimony of humanity" that should be nurtured and protected.

She worries that globalization is disconnecting Mexicans from their very life source, be it U.S. corn displacing ancient strains of maiz or fast food encroaching on the traditional comida, or leisurely afternoon meal.

"For Mexicans, food is basically culture. The act of eating here in Mexico is an act of enormous significance," she said. "We have entered a period of threat, of crisis."

Nutritionists likewise are alarmed that instant ramen, a dish loaded with fat, carbohydrates and sodium, has become a cornerstone of the food pyramid.

With the majority of the population now urbanized and on the go, Mexicans are embracing the convenience foods of their neighbors in the United States while abandoning some healthful traditions. The result is soaring levels of obesity, diabetes and heart disease, particularly among the poor.

"It's cheap energy," said Gustavo Acosta Altamirano, a nutrition expert at Juarez Hospital in Mexico City, referring to the nation's growing addiction to soft drinks, sugary snacks and starchy foods like ramen noodles. "But it's making us fat."

Instant ramen has its roots in aching hunger. It was invented by Momofuku Ando, an entrepreneur whose businesses crumbled with Japan's defeat in World War II.

Memories of shivering Japanese lined up for a bowl of noodles in bombed-out Osaka haunted Ando for years, he wrote in his autobiography, "My Resume: The Story of the Invention of Instant Ramen."

Ando, now 95, founded Nissin Food Products Co. in that city, guided by the mantra: "Peace follows from a full stomach." He figured out that frying fresh ramen was the key to preserving the noodle and making it porous, so that it could be reconstituted with boiling water into fast, cheap nourishment.

Instant ramen hit the Japanese market in 1958 and became an immediate sensation. The product is such an icon in Japan that thousands visit Nissin's ramen museum each year to see a replica of the tiny backyard workshop where Ando cooked up his invention.

The most economical version is sold in plastic-wrapped, dehydrated squares that consumers typically heat in saucepans on the stove. The average U.S. price is 14 cents per package, thanks to highly automated manufacturing in plants on American soil.

Most of Mexico's ramen is imported and served in insulated, disposable cups, which drives the price up to about 35 cents. Most of that product is manufactured in Southern California, where Japanese food giants Nissin and Tokyo-based Toyo Suisan Kaisha Ltd., maker of the Maruchan brand, have their U.S. headquarters.

Asian nations remain the world's top consumers. The Chinese alone ate nearly 30.5 billion servings last year. Outside that region, only the United States, Russia and Brazil gobbled more instant ramen than Mexico. But in Latin America, Mexico is the noodle champ. Its consumers ate an average of 9.4 servings in 2004 compared with just over six bowls for those in runner-up Brazil, according to the Japan-based International Ramen Manufacturers Association.

The most popular brand here is Maruchan, whose logo of a cheerful, round-faced boy peeps out from stores shelves nationwide.

Maruchan executives declined to be interviewed. But with a Mexican market share estimated at about 85 percent, the brand is impossible to ignore. Like Band-Aid bandages and Kleenex tissues in the United States, Maruchan has become the generic term for ramen noodles in Mexico.

That's clearly an irritation to Nissin. "We call them copycats," Takayuki Naruto, president of Nissin Foods (USA) Co., said in an interview at the company's U.S. headquarters in Gardena, Calif.

In a giant warehouse of Diconsa, a government agency that distributes food to the rural poor, cases of Maruchan are stacked on pallets, along with staples such as powdered milk, flour and cooking oil. The agency began stocking the noodles about five years ago after managers of government-subsidized country stores reported that their customers were clamoring for them. Diconsa purchased about 5.5 million pounds of Maruchan last year, nearly triple the amount it bought in 2000.

Miguel Angel Ansareo Mogollon, manager of the central warehouse located outside Mexico City, said rural women busy with children and chores were influenced by television advertising.

A cup of instant ramen costs 4 pesos, or about 37 cents in Diconsa-affiliated shops. A serving of beans costs pennies in comparison. Still, the average Mexican's bean consumption has dropped by more than half since 1995, according to an agriculture trade group. Per capita consumption of tortillas has declined precipitously as well.

"Traditions are changing fast, even up in the mountains and in the countryside," Ansareo said. "You can spend days cooking beans. Maruchan is ready in three minutes. All the mother has to do is boil the water and throw in the chilies."