With the arrival of 2020, many people have begun their New Year’s resolutions to get healthier and lose weight. Is “diet” soda the secret to weight loss success? Not according to the Ninth Circuit, which held last week that it is not reasonable to believe that drinking “diet” soda will help in efforts to lose weight and affirmed dismissal of a false advertising lawsuit.

In the case, Becerra v. Dr. Pepper/Seven-Up, the plaintiff alleged that the word “diet” in Diet Dr Pepper’s brand name violated various California laws, including the state’s False Advertising Law, because it falsely promised that the product would assist in weight loss or healthy weight management. The plaintiff alleged that this was false because an ingredient in the diet soda, aspartame, causes weight gain.

The district court granted defendant’s motion to dismiss without any discovery. In granting the defendant’s motion to dismiss, the district court held that no reasonable consumer would believe that the word “diet” in a soft drink’s brand name promises weight loss or healthy weight management. And, the district court held, even if a reasonable consumer would believe that, the plaintiff had not sufficiently alleged that any such promise was false or that aspartame consumption causes weight gain.

On appeal, the Ninth Circuit agreed. Applying the “reasonable consumer” test to plaintiff’s claims, the Ninth Circuit found that plaintiff needed to “show that members of the public are likely to be deceived.” This, in turn, required more than a mere possibility that Diet Dr Pepper’s label “might conceivably be misunderstood by some few consumers viewing it in an unreasonable manner.” Rather, the reasonable consumer standard requires a probability “that a significant portion of the general consuming public or of targeted consumers, acting reasonably in the circumstances, could be misled.”

Applying this standard, the court found that the word “diet” in Diet Dr. Pepper’s name meant “reduced in or free from calories,” instead of promising weight loss or management. Further, the court concluded that “diet” was understood as a relative claim about the calorie content of the soft drink compared to the same brand’s regular option. Accordingly, the court found that the plaintiff failed to sufficiently allege that reasonable consumers read the word “diet” in a soft drink’s brand name to promise weight loss, healthy weight management, or other health benefits. Without this, the plaintiff’s claims failed.

The Ninth Circuit’s decision follows the Second Circuit’s decisions in other lawsuits against soda manufacturers, which held that the term “diet” refers specifically to the drink’s low caloric content and does not convey a more general weight loss promise. Thus, although not new, the Ninth Circuit’s decision provides a clear and recent signal of where the court stands on the issue.

The case also has broader application outside of the “diet” space. Critically, the Ninth Circuit held that it was appropriate to grant a motion to dismiss for failure to state a claim — a motion based solely on the allegations in the plaintiff’s complaint without any discovery — where the plaintiff had not alleged that reasonable consumers would interpret a term in the way plaintiff did. And the Ninth Circuit noted that just because some consumers may unreasonably interpret the term differently does not render the use of “diet” in a soda’s brand name false or deceptive or lead to a false advertising case.

Thus, if a court concludes — on a motion to dismiss — that no reasonable consumer would interpret a challenged advertisement in the way that a plaintiff did, then the judge can dismiss the case instantly. As a result, class action plaintiffs may think twice when arguing that consumers interpret a term in a certain way. However, it’s yet to be seen how this will affect class action plaintiffs’ resolutions in bringing future false advertising cases.