Healthy weight and lifestyle advertisements: an assessment of their persuasive potential.

This study aimed to identify and analyse the content of previously produced and aired adult-targeted public health advertisements (ads) addressing weight, nutrition or physical activity internationally. Ads were identified via keyword searches of Google, YouTube and websites of relevant government agencies and health organizations, and were eligible for inclusion if they were: in English; produced between 2007 and 2012; targeted at adults; ≤60 s; not promoting a particular commercial brand of food, fitness or weight loss product. Of the 99 ads coded, 59% featured supportive/encouraging messages, 36% presented information about health consequences and 17% focussed on social norms/acceptability issues. Supportive/encouraging messages were more frequently used in physical activity ads, while there were a higher proportion of messages about health consequences in weight ads. Execution style differed across lifestyle topics, with simulation/animation more common in nutrition ads and graphic images and negative personal testimonials in weight ads. Ads addressing weight were more likely to evoke high negative emotion and include potentially stigmatizing content. Understanding how weight and lifestyle issues have been addressed in recent public health advertising will help guide future efforts to test the effectiveness of different message types in facilitating positive behaviour changes.