Fat city: the obesity crisis that threatens to overwhelm Mexico's capital

Even the diets of newborn babies might bear some influence: in Mexico City in 2012, just 9% of babies from zero to six months were breastfed exclusively, compared with 14% of babies in the rest of the country.

However, while the precise nature of the city’s dietary problems is hard to pin down, the picture regarding physical activity is much clearer. Put simply, the Federal District is the most sedentary state in the country.

In 2012, only 33% of children aged 10 to 14 years reported doing any significant form of exercise – dancing, or sports such as basketball and football – over the previous year, while 74% of children said they looked at a screen for more than three hours every day during the week. As for the adult population, last year 29% of workers were employed in sedentary jobs, either working in an office or sitting elsewhere in front of a screen.

The explanation for this chronic lack of exercise probably lies with the urban environment – and the lifestyle that is encouraged – and discouraged – by the city’s structure and dynamics.