Evaluation of the impact of the Bristol’s outdoor advertisement restrictions policy on self-reported exposure to advertisements, consumption and use of unhealthy commodities.

Background Policies restricting advertisements of high fat, salt and sugar (HFSS) products and other unhealthy commodities are potentially effective tools to improve diet, reduce diet-related diseases and address public health inequalities. Bristol was the first UK city outside London to introduce such a policy on council-owned advertisement spaces in 2021. This study evaluates the policy’s impact on self-reported exposure to advertisements of HFSS products, alcohol and gambling, and self-reported consumption or use of these products. Methods A repeated cross-sectional survey of Bristol residents (intervention) and neighbouring South Gloucestershire residents (comparator) was administered before (n = 2,543) and after (n = 2,076) the policy was implemented. Self-reported exposure to outdoor adverts on HFSS products, alcohol and gambling in the local area and consumption or use of these products was collected, along with socio-demographic information. The intervention effect was analysed using a weighted controlled before-after design. Result Following the policy, there was no evidence of a change in self-reported exposure to advertising of unhealthy commodities, compared to the comparator group; percentage point change in exposure to advertising was − 6.9% (95% CI -34.9, 35.0) for any unhealthy commodity, -19.2% (95% CI -45.1, 17.4) for HFSS foods/drinks, 33.6% (95% CI -14.8, 100) for alcoholic drinks and − 8.6% (95% CI -38.1, 36.3) for gambling. Likewise, there were non-significant changes in self-reported consumption of HFSS products (-2.0% (95% CI -49.3, 89.6), alcohol (15.0% (95% CI -18.9, 64.9) and participation in gambling (-17.3% (95% CI -45.7, 25.9) following the introduction of the policy in Bristol, compared to comparators. Conclusions Following the implementation of the policy there was no measurable reduction in self-reported exposure to outdoor advertising of unhealthy commodities, nor was there much evidence of changes in reported consumption of HFSS products, alcohol or gambling. This may be attributable to the relatively small Council-owned outdoor advertisement estate (~ 30%), so changes in exposure may have been too small to lead to noticeable effects. However, this policy aligns with Bristol City Council’s ‘Health in all Policies’ approach aimed to support a systems-wide approach to improve health.