In February 2020, San Francisco proposed mandatory health warnings for sugar-sweetened beverage (SSB) advertisements. Industry legal challenges stated that the warning would detract from advertisers’ ability to convey their intended message and mislead consumers into believing that SSB cause weight gain regardless of consumption amount, lifestyle or intake of other energy-dense foods.

Online between-group experiments tested the impact of SSB warnings on advertising outcomes and consumer perceptions. Respondents were randomised to view six SSB print advertisements with or without a health warning (‘Warning’ and ‘No Warning’ condition, respectively). Linear and binary logistic regression models tested differences between groups, including ad recall, brand perceptions and beliefs about SSB health effects.

Panelists from the US Nielsen Global Panel.

Sixteen to 65-year-old respondents (n 1064).

Overall, 69·2 % of participants in the ‘Warning’ condition recalled seeing warnings on SSB ads. Compared with the ‘No Warning’ condition, participants in the ‘Warning’ condition who reported noticing the warnings were equally likely to recall the brands featured in the SSB ads and to recall specific attributes of the final ad they viewed. Similarly, no differences were observed between groups in perceptions of SSB, such as perceived taste, or in the prevalence of false beliefs regarding the health effects of SSB and intake of other sugary foods on weight gain.

Overall, there was no evidence that SSB health warnings detracted from attention to promotional elements in advertisements or that the warnings misled consumers into false beliefs about SSB as the exclusive cause of weight gain.