Study Reveals Junk Food Ads Drive Higher Calorie Intake in Children

New Delhi: Exposure to junk food advertising significantly increases calorie consumption among children and adolescents, regardless of the media format or ad content, according to a new randomized crossover trial presented at the 2025 European Congress on Obesity. The study, led by researchers from the University of Liverpool, found that even five minutes of exposure to advertisements for high-fat, salt, and sugar (HFSS) foods caused children to consume an average of 130 extra kilocalories in a single day—the equivalent of two slices of bread.

The trial involved 240 children aged 7–15 from schools across Merseyside, UK. On separate occasions, participants were shown five minutes of HFSS food advertisements and non-food advertisements across four media formats: audiovisual (e.g., TV), visual (e.g., social media), audio (e.g., podcasts), and static (e.g., billboards). The ads included both product-based and brand-only formats. Following the exposure, researchers measured the children's ad libitum snack and lunch intake, body mass index (BMI), and socioeconomic status using postcode data.

Children exposed to HFSS ads consumed significantly more food than those exposed to non-food ads—an average of 58.4 extra kilocalories from snacks and 72.5 from lunch. Remarkably, the study found that the type of media and the ad content (brand-only versus product-based) did not moderate the effect. "Our findings offer crucial novel information on the extent, nature, and impact of unhealthy food marketing via different types of media on young people's eating behavior," said lead author Professor Emma Boyland from the University of Liverpool in the UK. "Even short exposure to marketing of foods high in fat, salt, and sugar can drive excess calorie consumption and potentially weight gain, particularly in young people who are more susceptible to advertising and whose eating patterns influence their lifelong health."

The researchers also observed that children with higher BMI consumed even more calories after viewing HFSS ads.

Reference: European Association for the Study of Obesity