MEXICO CITY — Dressed in the hand-woven red cloths of her native village and chatting away in her ancient Nahuatl tongue, Pilar Blanco and her family sit down to dinner in what looks like an age-old meal time ceremony.

But when Hernandez serves up the food, there is one major difference from tradition: instead of tortillas and beans, the family eats instant noodle soups, potato chips and fizzy soda.

“I’m out working all day cleaning people’s houses and I have no time to cook. So the instant soups are a big help,” Hernandez explains, sitting with her husband and three children in a cinder block home on the outskirts of this sprawling capital.

Such radical changes in diet have swept through Mexico in the last decade leading to an explosion of obesity. As families guzzle evermore processed food, hamburgers and french fries, they have piled on the pounds to make Mexico one of fattest nations on the planet.

Studies by the Health Department show that a startling 68 percent of Mexican adults are overweight and 29 percent are obese — just behind the United States, where 74 percent are overweight and 39 percent obese.

Only the tiny Pacific island nations of Samoa and Tonga have heavier populations.

There is particular concern about the rising weight of Mexican children. The Mexico City government announced this month that an alarming 35 percent of school pupils are over the recommended bodyweight.

To try to fight back, the government has kick-started an anti-obesity campaign of sporting events and healthy-eating propaganda aimed at the young.

“We need you children to understand the importance of taking care of your health and the problem of obesity that is worrying to our country,” Mexico City Health Minister Armando Ahued told 1,000 children panting away in a running race. “You are the future of the capital, and we need you to avoid getting diseases such as diabetes and hypertension.”

The campaign is also encouraging young people to lose pounds by joining 11,000 dancers in the largest-ever routine of Michael Jackson’s song "Thriller," scheduled for Aug. 29 in Mexico City’s central plaza.

The changing dietary habits have come as Mexico has switched from a largely protectionist to an extremely globalized economy.

Since it enacted the North American Free Trade Agreement in 1994, imports of processed food and drinks have soared.

The nation now consumes more Coca Cola products per capita than anywhere else in the world: a total of 635 eight-ounce bottles per person each year. The amount represents a threefold increase compared to 1988.

In many villages in Mexico’s mountains and jungles, it is easier to get a bottle of soda than drinkable water.

In addition to fattier diets, changing lifestyles have also made people put on the pounds.

More and more Mexicans are abandoning hard-working country jobs for ever expanding urban jungles such as the capital with its 20 million inhabitants or Tijuana, which grows by a block a day.

There are also more and more cars. The country's denizens collectively buy more than a million vehicles a year amid cheaper prices and better credit.

Furthermore, a wave of violent crime makes many parents keep their children at home under their careful eye rather than letting them play on the mean streets.

Policemen themselves have also suffered from the obesity epidemic, undermining their efforts to make these streets safe again. This month, the Public Safety Department called on police to drink more water, eat more healthily and do more exercise to project a better image. The department also sent in a force of 53 experts to train officers to lose weight and engage in sports such as boxing.

As in the United States, Mexico’s growing waistlines have put immense pressure on the nation’s health care system.

Obesity-related diseases cost countless billions in medical attention and lost work hours.

Health officials are particularly concerned about diabetes, with studies showing that Mexicans’ genes make them particularly prone to the condition.

“The vulnerability to diabetes comes from both the Indian and Spanish heritage so we are doomed in this sense,” said Amanda Galvez, an investigator at Mexico’s National Autonomous University. “If we keep eating the way we are eating and if we don’t exercise we will all end up having diabetes.”

Galvez warns that the worst pressures on the health care system could still be to come.

Many people who have suffered from the obesity epidemic are just reaching middle or old age when they are more prone to crippling diseases.

Mexico’s most high-profile obesity case entered the Guinness book of records when he went on television to weigh in at 1,235 pounds in 2006.

Since then, Manuel Uribe followed a special diet to drop to 800 pounds.

The 400-pound loss is one of the biggest weight reductions in medical history.

“If I can do it, then others can too,” Uribe told reporters as he celebrated the achievement with a band of mariachis last year.

The Mexican government hopes more of it citizens will make such efforts.