Four years after Chile embraced the world’s most sweeping measures to combat mounting obesity, a partial verdict on their effectiveness is in: Chileans are drinking a lot fewer sugar-laden beverages, according to study published Tuesday in the journal PLOS Medicine.

Consumption of sugar-sweetened drinks dropped nearly 25 percent in the 18 months after Chile adopted a raft of regulations that included advertising restrictions on unhealthy foods, bold front-of-package warning labels and a ban on junk food in schools. During the same period, researchers recorded a five percent increase in purchases of bottled water, diet soft drinks and fruit juices without added sugar.

“An effect this big at the national level in the first year is unheard-of,” said Lindsey Smith Taillie, a nutrition epidemiologist at the University of North Carolina, Chapel Hill, and the study’s lead author. “It is a very promising sign for a set of policies that mutually reinforce one another. This is the way we need the world to go to begin to really combat preventable diseases like obesity, hypertension and diabetes.”

The rules, adopted in 2016, were a bold gambit by the government of a country with some of the world’s highest obesity rates. Three-quarters of Chilean adults and more than half of children are overweight or obese, and health officials warned that the medical costs of obesity could consume 4 percent of the nation’s health care spending by 2030, up from 2.4 percent in 2016.