San Francisco recently became the first city in the nation to mandate public safety warnings about the health effects of sugar. Beginning July 25, publicly-displayed advertisements around the city for sugar-sweetened beverages must include a warning label that takes up 20% of the display space.

San Francisco U.S. District Judge Edward Chen ruled in favor of the warning labels earlier this month following a lawsuit from the American Beverage Association, the California Retailers Association, and the California State Outdoor Advertising Association, who all claimed the measure infringed upon free speech rights.

“The warning required by the city ordinance is factual and accurate,” Chen said in his ruling, “and the city had a reasonable basis for requiring the warning given its interest in public health and safety.”

The label is set to read: “WARNING: Drinking beverages with added sugar(s) contributes to obesity, diabetes, and tooth decay. This is a message from the City and County of San Francisco.” It applies to posters and billboard advertisements for beverages with more than 25 calories per 12 ounces due to added sugars, but not to print ads, television commercials, or label packaging.

The American Beverage Association, a lobby group that represents industry giants such as Coca-Cola and PepsiCo, argued that the city is “unfairly discriminating against one particular category of products, based on one ingredient found in many other products.”

The city of San Francisco’s defense provided the court with evidence that sugar-sweetened beverages are “a significant source of calories” and that companies target low-income demographic areas who are “particularly affected by added sugars in their diets” and more susceptible to diseases like obesity, diabetes, and tooth decay — the latter of which affects some 31% of all adults today.

San Francisco’s initiative is being hailed by public health groups as a major step forward for federal regulation of the sugar industry. “We believe there will be a wave of similar legislation across the country,” Dr. John Maa of the American Heart Association told the San Francisco Gate, “and we believe this will improve the health of America.”