The Association of National Advertisers has joined the fight by filing an amicus brief with the federal court in San Francisco in a challenge to the City of San Francisco ordinance that mandates warnings for sugar-sweetened drinks.

Last year, the San Francisco Board of Supervisors adopted new health code provisions with regard to sugar-sweetened beverages, including a law requiring the addition of a warning label to the advertising for covered drinks. The law requires that the label cover at least 20 percent of the ad for beverages that have 25 calories or more of sugar per 12 ounces (with an exception for alcoholic beverages, certain juices, and milk products, and ads on television, the Internet, or other electronic media) with a statement that "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."

The American Beverage Association, California Retailers Association, and California State Outdoor Advertising Association filed suit to halt enforcement of the law, and in advance of a hearing on the request for an injunction, the ANA jumped into the fray.

San Francisco's Board of Supervisors "predicated their highly restrictive action on the dangerous theory that local officials may constitutionally commandeer space on certain types of advertisements whenever they feel like sending a government message," the ANA wrote, and the measure "conflicts with decades of judicial decisions holding it is 'incompatible with the First Amendment' to censor or otherwise burden speech based on fear that people will make bad decisions or to promote 'what the government perceives to be their own good.' "

If the court were to approve the requirement "there is no reason the San Francisco Board of Supervisors could not do so for a multitude of other products, as could every one of the some 30,000 city, town, and county governments in the United States," the group told the court.

"[T]he Board flaunted Supreme Court decisions that stress how 'speech regulation cannot unduly impinge on the speaker's ability to propose a commercial transaction and the … listener's opportunity to obtain information about products,' " according to the amicus brief. "There is no justification for the Warning Mandate in which the government commandeers space on private parties' ads in order to control public debate and alter individual behavior—purposes foreign to the First Amendment."

The ANA questioned not only the constitutional basis for the warning label but the strength of the science behind the message. The Board relied upon the U.S. Department of Agriculture's dietary guidelines, which are currently in the process of being revised, the group noted, as well as other research that has been the subject of reversals and revisions. "The San Francisco Board of Supervisors, of course, is not itself expert in science in nutrition, and should receive no more deference than the national health organizations on which they rely," the brief added.

The ANA argued that the warning label law was not narrowly tailored and lacks a rational basis as a means to address the Board's purported concerns in enacting the law. For example, "there are many alternatives at its disposal, besides burdening ads with compelled speech," the group wrote. They suggested that the city design its own messages to educate consumers or persuade them to change their consumption patterns or to adopt a so-called "soda tax."

"The City of San Francisco's imposition of the Warning Mandate in reaction to potential over-consumption of sugar-sweetened beverages by its citizens, whatever the merits of that concern, takes regulatory Nannyism to new levels and is wholly incompatible with First Amendment protections afforded to commercial speech," the ANA concluded.

To read the ANA's amicus brief in The American Beverage Association v. The City and County of San Francisco, click here.

Why it matters: The ANA pointed out that similar efforts in other jurisdictions—notably, New York City's attempt to ban "giant soda"—have failed judicial review. "If this Court were to uphold the Board of Supervisors' conscription of sugar-sweetened beverage ads to convey government views on health issues there would be virtually no limit to similar efforts targeting other products, at any level of government," the group cautioned. "Advertisers would face that risk tens of thousands of times over, from any city, town, county, or other municipal authority with a particular health-related hobby horse." A hearing in the case is scheduled for April.