Anais Martinez is on the hunt in Mexico City's Merced Market, a sprawling covered bazaar brimming with delicacies. "So this is the deep-fried tamale!" she says with delight, as if she'd just found a fine mushroom specimen deep in a forest.
The prized tamales are wrapped in corn husks and piled next to a bubbling cauldron of oil.
"It's just like a corn dough patty mixed with lard, put in a corn husk or banana leaf, steamed and then deep fried," says Martinez of this traditional Mexican breakfast. "And then after you fry it, you can put it inside a bun and make a torta [sandwich] out of it. So it's just like carbs and carbs and fat and fat. But it's actually really good."
And it only costs 10 pesos — roughly 50 cents.
Martinez is a designer in Mexico City. She studied gastronomy here and now moonlights for a company called Eat Mexico giving street food tours.
Deeper in the market there's an area packed with taco stalls. Customers stand at the counters or sit on wobbly plastic stools. The young cooks fry, flip and chop various meats into tortillas. They pound strips of flank steak out on wooden cutting boards. Piles of red chorizo sausage simmer in shallow pools of oil. Yellow slabs of tripe hang from meat hooks.
We've just come to one of Martinez's favorite taco stands. Its specialty is pork tacos served with french fried potatoes piled on top.
"The pork is really thinly sliced, rubbed with chiles and spices and then they fry it," Martinez says as the meat sizzles on a long steel griddle in front of her. "Also, really good."
Rich, fatty street food like this is available all over Mexico — at bus stops, at schools and on street corners. And it's affordable to the masses. A heaping plate of Martinez's favorite pork tacos costs less than a dollar.
All that cheap food — in a country where incomes are rising — is contributing to Mexico's massive diabetes epidemic.
Diabetes is now the leading cause of death in Mexico according to the World Health Organization. The disease takes an estimated 80,000 lives each year. Nearly 14 percent of adults in this country of 120 million suffer from the disease — one of the highest rates of diabetes in the world. And it's all happened over the last few decades.