Latin America labels ultra-processed foods. Will the US follow?

In 2010, Mexico led the way, followed by Ecuador, Chile, Peru, Uruguay, Argentina and Colombia

• What are those weird ingredients in our favorite packaged foods?

Candy lines every inch of the mercado de dulces in Mexico City's historic center. Tantalizing strawberry-flavored chocolates and Tajin-covered mango gummies pack the narrow aisles of the meandering marketplace. But many of the colorful packages are somewhat dampened by black stop signs printed on their fronts. Alongside dreamy descriptions of creamy and chocolatey confections, the stop signs warn Excess calories" or Excess sugars". For some customers, the warnings are enough for them to pause and reconsider their purchases.

Latin America is leading the world in a movement to print nutritional warning labels on the fronts of food packages. Currently, the labels warn when a food product exceeds a consumer's daily recommended value of any nutrient of concern" - namely, sugar, salt or saturated fat (some countries have added trans fats, artificial sweeteners and caffeine). But research led by scientists across the continent is increasingly pointing towards another factor consumers may want to consider: how processed a food is.