Mexico City, Mexico - Mexicans have always loved to eat and drink, but rapidly changing dietary habits have created a nation in danger of eating themselves to death.

Mexican schoolchildren are now some of the fattest in the world, with one in three classified as overweight or obese - a 27 percent rise in 12 years, according to the latest National Survey of Health and Nutrition. Their parents also score high on global ranking tables - weighing in second behind only the United States.

Among adults, a staggering 73 percent of women are overweight or obese; men are only marginally thinner, with 69 percent "abnormally" sized. The National Survey reveals what is obvious to even an untrained eye: people of a "normal" or healthy weight are becoming a rare breed in this food-obsessed country.

Mexico's biggest killers are now cardiovascular diseases - including heart failure, myocardial infarctions (heart attacks) and strokes - and diabetes. Together these accounted for 150,000 deaths in 2012, according to World Health Organisation figures.

Yet only 40 years ago, the main causes of death here were malnutrition and infectious diseases. The speed at which Mexicans have made the change from a diet dominated by maize and beans to one that bursts at the seams with processed fats and sugars poses one of the greatest challenges to public health officials.

"No other country has grown like Mexico," said Juan Rivera Dommarco, assistant director of the Centre of Investigation in Nutrition and Health at the National Institute of Public Health. "It has taken Mexico only 12 years or so to do what other countries needed 60 years for."

Fried food and soda

There are about 21 million clinically obese adults in Mexico - that's an incredible 38 percent rise since 2000, the health survey reveals. Diabetes rates doubled in this period - one of the most rapid growths seen anywhere in the world. You don't have to look further than the bustling streets of any town or city to start to understand why.

"My daughters are always asking for refrescos, but I try to lead by example so the whole family only drinks water or fresh juices... The streets are full of fatty foods because Mexicans don't want to eat vegetables any more. - Abraham Cruz Diaz, carpenter

The pavements are saturated with vendors selling calorific snacks: deep-fried pork skin, beef tacos, doughnuts, ice cream, quesadillas filled with cheese, hot dogs, hamburgers, with freshly made potato crisps, and deep-fried plantain - sometimes the only vegetables in sight.

The nation's famous sweet tooth has been successfully exploited by the fizzy drinks industry. Mexicans drink more "refrescos" than any other country. Seven out of ten children in rural communities have a sugary drink with breakfast, according to the campaign group Power of the Consumer.

Research presented at an American Heart Association conference in March found that sugary drinks accounted for 22,000 deaths in Mexico every year - the highest rate in the world. The television, billboards and markets are awash with advertisements, in Spanish and indigenous languages, for processed snacks and sugary drinks by companies such as Nestle, Pepsi, Coca Cola and Bimbo.

Children in particular are bombarded with advertisements, with few regulations to restrict marketing. Abraham Cruz Diaz, a 44-year-old carpenter with daughters aged five and eight, said the ads targeting children are relentless.

"My daughters are always asking for refrescos, but I try to lead by example so the whole family only drinks water or fresh juices.

"It is hard always saying no: refrescos are everywhere and only five pesos [30 cents] and the streets are full of fatty foods because Mexicans don't want to eat vegetables any more. I try to explain that if they look after their bodies now, they will live ten years longer."

'Public health emergency'

Research by Professor Barry Popkin, a global obesity expert from the University of North Carolina, was the first to show Mexicans drink more sugary drinks than any other nation.

"Marketing of sugary beverages is the most important factor that we have found [in Mexico]," Popkin said. "Calories from beverages doubled between 1999 and 2006. Second, snacking is way up - again, probably a demand created by marketing. And third, the huge growth of convenience stores and modern mega-food markets."

Though traditionally regarded as a rich-man's disease, diabetes is wreaking havoc in low- and middle-income countries, where four out of five diabetics now live, according to the International Diabetes Federation.

In Mexico, 6.4 million - or one in 10 - adults is diagnosed with diabetes, the sixth-highest rate in the world. Another 3.6 million people are thought to have the disease, but are unaware.

Health Minister Mercedes Juan Lopez recently described the massive rise incidence as a "true public health emergency".

A genetic predisposition means Mexicans are more prone to diabetes than Caucasians. Even among those who are diagnosed, figures from the national survey suggest three-quarters have poorly controlled blood sugar levels, placing them at a much higher risk of long-term disabling and fatal complications. Already it is the biggest-single cause of blindness in adults and a major cause of amputations, said the Mexican Diabetes Federation.

Dr Stan De Loach, an American diabetologist, has been treating adults and children in Mexico for more than 40 years. "Diabetes and obesity are the country's biggest silent deadly diseases," he told Al Jazeera. "But most people are so addicted to carbohydrates that they aren't willing to do anything about it until the complications set in, and then it's too late."

Government response

The government has introduced a range of measures to try and curb the tsunami of fat. In a recent speech, President Enrique Pena Nieto said: "We must banish this idea of health as a cure and move towards a comprehensive prevention concept, associated with healthy lifestyles."

Last year it introduced the so-called "sin taxes" on sugary drinks, and in 2011 published guidelines to restrict junk food being sold in schools - though a proposed list of banned products was successfully opposed by the food and drinks industry.

As part of a new national exercise campaign, the government enlisted revered wrestling stars to try to get kids active: Lucha Libre against Obesity. Currently, 60 percent of 10- to 14-year-olds perform no sport at all, according to the survey.

We must banish this idea of health as a cure and move towards a comprehensive prevention concept, associated with healthy lifestyles. - Mexican President Enrique Pena Nieto

The government is undoubtedly alarmed at the spiralling costs associated with obesity. The direct and indirect cost is expected to double from $6.5bn now to $13.7bn in 2017, according to department of health figures.

Recent initiatives have been welcomed, but they fail to tackle the fundamental causes, said Alejandro Calvillo, director of Power of the Consumer.

"Formula milk, instant soups and sugary sodas have replaced breast-feeding, maize, beans and water, and children become addicted to sugar from a very early age. Kids in rural areas of Chiapas and Guerro are malnourished but overweight," Calvillo said.

His organisation is part of the Nutritional Health Alliance that campaigns for effective government policies to combat obesity and malnutrition. They want restrictions on the marketing of junk foods, improved food labelling, clean drinking water fountains in public places, support for local, fresh produce, and national campaigns to promote breast-feeding and filtered tap water.

"When 70 percent of people are overweight or obese, then it is not only about bad personal choices. Their environment is developing this epidemic, and so government policies need to change this environment," Calvillo said.

Despite the obesity epidemic, malnutrition still kills about 9,000 people annually, mainly young children in poor rural states. However, the Alliance is highly critical of the government's highly publicised Crusade against Hunger. Pepsi and Nestle were announced as key partners, even before a scientific advisory committee was established.

For Professor Popkin, the two biggest challenges facing the nation's battle against the bulge are: "Getting major government action in the face of very organised food industry lobbying, and Mexicans' preference for extreme sweetness."

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