Abstract
BACKGROUND: The advertising of unhealthy foods has been recognized as a significant contributor to childhood overweight and obesity. In China, childhood obesity has become an escalating public health concern. Despite this, data on outdoor food advertising, one of the most common advertising forms that children encounter in their daily lives is not well documented in China, leaving gaps in an understanding of its exposure, impact and implications for policy interventions. Collaborating with UNICEF China, this study investigated outdoor advertising in 3 key settings (roadside environment around schools, high-rise apartment communities, and public transit systems), aiming to fill these gaps and support a healthier environment across China. METHODS: Multi-stage stratified random sampling methods were utilized to select investigated schools, high-rise apartment communities, and public transit systems in Chengdu. The INFORMAS Outdoor Advertising Protocol guided the selection of the physical routes covered in the investigations, while WHO Nutrient Profile Model for the Western Pacific Region served as the technical basis for categorizing the food items advertised. At the same time, advertising themes in outdoor advertisements of unhealthy foods were identified through qualitative coding and content analysis. RESULTS: A total of 998 outdoor advertisements were observed around 25 schools, of which 439 (44.0%) were food advertisements. 308 (70·2% of all food advertisements) were for unhealthy foods. In 903 high-rise apartment communities, 2864 distinctive print advertisements and 1174 non-repetitive video advertisements were recorded, with approximately one-third (32·6%&35·5%, respectively) food-related, and over half of food-related advertisements through each medium (52·8%&64·4%, respectively) marketing unhealthy foods. In public transit, 3385 advertisements were collected through 70 bus routes and Metro Line 1 to Line 8, including 232 (6·9%) food advertisements, with 114 (49·1%) for unhealthy foods. Along children’s daily commute routes, sugar-sweetened beverages and alcoholic beverages were the most frequently advertised unhealthy foods. Outdoor food advertisements in Chengdu, especially those for unhealthy foods, are mainly concentrated in central city. Video advertisements for unhealthy foods in residential buildings employed various marketing strategies, with taste appeal, nutrition/health claims, and promotional characters being the most prevalent themes. CONCLUSION: School-age children in Chengdu are highly exposed to outdoor advertisements for unhealthy foods, with residential building elevators serving as a major hotspot for such advertising. Strengthening policy oversight of outdoor advertising for unhealthy foods is a crucial measure for preventing childhood obesity.