Unhealthy Food and Beverage Marketing on Public Transport Infrastructure in Western Melbourne.

BACKGROUND

Unhealthy and ultra-processed food (UPF) consumption leads to dietary pattern changes, a deterioration of diet quality, and increases the risk of chronic diseases. Marketing of UPF on government-owned assets, such as public transport infrastructure, contributes to their repeated exposure to the public, increasing consumption.

OBJECTIVE

To quantify food and beverage marketing on public transport infrastructure in Western Melbourne, assess the proportion of advertising for unhealthy and ultra-processed food, and explore the relationship between unhealthy advertising and socioeconomic disadvantage.

METHODS

We performed a cross-sectional study at all bus stops, tram stops and train stations in three local government areas (LGAs) in Western Melbourne. We grouped food advertisements using a modified classification from existing protocols and performed descriptive analysis by LGA and transport type. We evaluated the relationship between the proportion of unhealthy advertisements in each area and the index of relative socioeconomic disadvantage using Spearman's correlation.

RESULTS

Of 693 total advertisements, 229 promoted food or drinks. Three-quarters (174/229) advertised unhealthy products, most commonly sugar-sweetened beverages (49%) and unhealthy meals (28%). Overall, 73% of food advertisements promoted ultra-processed foods. Vending machines on train platforms accounted for 40% of all unhealthy advertisements. We found no statistically significant relationship between the proportion of unhealthy advertisements and socioeconomic disadvantage.

CONCLUSIONS

Unhealthy and ultra-processed food marketing dominates public transport food advertising in Western Melbourne. Advertising on public transport has a meaningful impact on communities' exposure to unhealthy foods and the risk of obesity and chronic disease.