A new study in Chile found that children aged four to six who attended school for 18 months after the first phase of the country's Food Labelling and Advertising Law were less likely to be overweight or obese. Researchers compared data from these students to those in the same grades before the law's implementation.

Chile implemented the Food Labelling and Advertising Law in 2016. This legislation targets foods and beverages high in sugars, saturated fats, salt, or calories. The law mandates front-of-package warning labels shaped as black octagons on these targeted products. It also restricts the sale of targeted food products within schools and limits food marketing directed at children.

The study analyzed national data on more than 300,000 schoolchildren aged four to six. Girls exhibited a 2.9 percent lower risk of overweight or obesity, representing a reduction of 1.4 percentage points from a pre-law rate of 47.7 percent. Boys exhibited a 2.4 percent lower risk, a reduction of 1.2 percentage points from a pre-law rate of 52 percent. Six months into the first phase, girls aged four to six showed a 1.9 percent lower risk of overweight or obesity, which was a reduction of 0.9 percentage points from a pre-law prevalence of 47.4 percent. Six months into the first phase, boys aged four to six showed a 2.2 percent lower risk of overweight or obesity, a reduction of 1.2 percentage points from a pre-law prevalence of 52 percent. Phases two and three of the law introduced stricter limits on sugars, saturated fats, salt, or calories in 2018 and 2019. The weight data for the study was collected by school staff, not primary healthcare professionals.