Edith Cowan University research: 15-second ads kick junk food cravings better than 30-second commercial

A 15-second television ad may pack more punch in the fight to beat junk food cravings than a traditional 30-second commercial. In a study of more than 500 Australian adults, researchers from Edith Cowan University found brief, positively framed health messages were able to curb immediate cravings for unhealthy food — and in some cases, outperform longer advertisements. The research, led by ECU psychologist Dr Ross Hollett, set out to examine what happened in the crucial moments immediately after someone watched a food advertisement. “Junk food advertising in Australia remains largely unregulated, despite significant public health concern,” Dr Hollett said. “We wanted to understand what actually happens in the moments after adults see junk food and anti-junk food ads.” Contrary to common assumptions, exposure to a single junk food advertisement did not significantly increase cravings or consumption intentions — even when viewers were shown foods they had previously nominated as favourites. By contrast, anti-junk food campaigns consistently reduced cravings and intentions to indulge. The detail that stood out was timing. Among participants in the normal body mass index range, a concise 15-second message had a stronger immediate effect than a longer 30-second version. “For some viewers, a short, sharp message may have more immediate impact than a longer ad,” Dr Hollett said. The tone of the message also mattered. For participants classified as overweight or living with obesity, advertisements that promoted healthier choices — rather than criticising junk food — proved more persuasive. “This suggests positively framed health messages may resonate more strongly with audiences carrying greater health risks,” Dr Hollett said. The findings point to a more nuanced approach to public health advertising at a time when governments continue to invest heavily in preventative health campaigns. “If we’re investing in public health campaigns, it’s important to know not just whether they work, but for whom and under what conditions,” Dr Hollett said. The research suggests that carefully targeted, upbeat and succinct campaigns may offer a practical counterweight to the steady stream of junk food marketing saturating Australian screens.