Results came from a study published online in Health Affairs, showing that sales of sugary drinks dropped by 5.5 percent in 2014 and by 9.7 percent in 2015. The largest reductions in sales were to those with the lowest incomes, who were also the ones with the highest risk of obesity-related diseases.

The tax was on all beverages that had added sugar; and that list included soft drinks, fruit drinks, and sweetened ice teas.

Earlier this year, France institute a nationwide ban on unlimited sugary drinks, making it illegal for anyone to sell more than one drink that has added sugars or sweeteners. Soda is the obvious target of the regulation, which also includes sports drinks, energy drinks, and non-soda soft drinks.

Soda taxes in the United States operate at the local or state level. Berkeley, Calif., was the first U.S. city to have a soda tax, in 2014. Four other cities passed similar taxes in 2016 (Boulder, in Colorado, Philadelphia, and California's Albany, Oakland, and San Francisco). New York has sought a similar tax as well.