Length and Framing of Anti‐Junk Food Ads Impact Inclinations to Consume Junk Food Among Normal Weight, Overweight, and Adults With Obesity

BACKGROUND: Unrestricted junk food advertising increases the risk of short-term junk food consumption among viewers. We aimed to estimate the impact of junk food and anti-junk food advertisements differing in length and framing on junk food consumption inclinations. METHODS: Adult participants (N = 505) were exposed to a randomly selected junk food advertisement or anti-junk food advertisement and reported their immediate craving and consumption intentions. These responses were separately analysed for two groups based on Body Mass Index (BMI): participants classified as within the normal range (18.5-25), and a combined group with BMI values indicating either overweight (25+) or obesity (30+) (OW/OB). A secondary analysis was also performed on a subgroup (N = 99) who were exposed to an advertisement containing junk food they reportedly enjoy consuming. RESULTS: For both BMI groups, junk food advertisement exposure did not increase immediate craving or consumption intentions. However, decreases were observed in craving and consumption intentions following anti-junk food advertisements. A 15-s anti-junk advertisement was more effective than a 30-s anti-junk advertisement for normal weight BMI participants. For OW/OB BMI participants, an anti-junk advertisement encouraging health food was more effective than an anti-junk advertisement criticising junk food. CONCLUSIONS: The effectiveness of anti-junk food advertisements varies depending on the length and framing of the advertisements as well as the viewer's BMI categorisation. These nuances are important for maximising the effectiveness of anti-junk food advertisements in different contexts. SO WHAT?: Given the potential for anti-junk food advertisements to curb consumption, a higher frequency of broadcasting brief positively framed health messages should be considered to mitigate the potential public health risks associated with junk food consumption.