Mexicans love their soda. Construction workers go to their jobs in the early morning clutching giant two-litre or even three-litre bottles. Babies in strollers suck on bottles filled with orange soda. In the highlands of Chiapas, Coca-Cola is considered to have magical powers and is used in religious rites.
In fact, Mexicans drink more soda than nearly anyone else in the world; their top three daily sources of calories in 2012 were all high-calorie drinks. Mexico also has by far the world's highest death rate from chronic diseases caused by consumption of sugary drinks – nearly triple that of the runner-up, South Africa. In other words, excessive consumption of soda kills twice as many Mexicans as trade in the other kind of coke that Mexico is famous for.
But Mexico also loves the soda industry. Vicente Fox, who in 2000 became the country's first democratically elected president, had earlier been president of Coca-Cola Mexico and then head of the company's Latin American operations. The symbolism was noteworthy: soda companies – particularly Coke, which controls 73% of the Mexican market (compared with only 42% in the US) – have amassed extraordinary influence over health policy in Mexico.
The consequences of this became apparent in 2006, when the release of Mexico's National Survey of Health and Nutrition revealed that diabetes – the country's leading cause of death – had doubled since 2000. Between 1999 and 2006, the average waist size among women of childbearing age increased by nearly 11cm. And during the same period, obesity among children aged five to 11 rose by 40%. No other country in the world had experienced a rise in obesity of that magnitude – Mexico was on its way to becoming the fattest major country.
The 2006 obesity statistics sounded an alarm in Mexico. The country's then health secretary, José Ángel Córdova Villalobos, approached Juan Rivera, the founding director of the Centre for Research in Nutrition and Health at Mexico's National Institute of Public Health – perhaps the country's most prominent nutrition scientist – and asked him for recommendations to combat the obesity epidemic.
Rivera laid out a programme, involving various parts of the government, to educate the public, encourage behaviour change, and regulate advertising, among other things. "That's very complicated," Córdova said. "You're an academic. I'm a politician – I'm very pragmatic. Choose one thing."
Reduce soda consumption, Rivera replied. The health survey showed that soda intake had more than doubled among adolescents between 1999 and 2006, and nearly tripled among women. So Rivera worked with a group of Mexican and US nutritionists to produce a diagram shaped like a jug with layers of various drinks to illustrate the ideal balance for daily beverage intake. The idea was to put a poster with the jug in every health centre. "It never happened," said Rivera. "Opposition from the industry was tremendous."
As Mexico began to grapple with obesity, and soda's role in it, the industry began to counterattack with the argument it uses everywhere that soda is under siege. "Obesity comes from taking in more calories than you spend," said Jaime Zabludovsky, chair of the board of ConMexico, the processed food and beverage producers' group. "If Michael Phelps eats 5,000 calories a day and swims 10km, there is no problem. If you eat 2,000 calories per day but don't move, you have a problem. The source can be soda, tortillas, chocolate, sandwiches, fritanga, bagels – there is not any product that in itself causes obesity."