The Devil is in the Detail: Challenging the UK Department of Health's 2019 Impact Assessment of the Extent of Online Marketing of Unhealthy Foods to Children.

Background: How much unhealthy marketing do children see on digital devices? Marketing of unhealthy food and beverages has long been identified as a factor in children’s preferences, purchase requests and consumption. Rising global obesity mandates States to craft environments that protect children and young people’s health, as recommended by the World Health Organization, among others. However, assessing the impact of marketing restrictions is particularly challenging: the complexity of digital advertising markets means that measurement challenges are profound. In 2019, the UK Department of Health published an Impact Assessment that applied a novel method aiming to calculate costs and benefits of restricting unhealthy food and beverage advertising on digital devices (planned for implementation by 2022). It estimated UK digital unhealthy marketing to children at 0.73 billion advertising impressions annually, compared to television impacts of 3.6 billion. Aim and Method: We assessed this conclusion by reviewing the UK Department of Health/Kantar Consulting’s Online Baseline Methodology (the “Government Model”). We examined the model’s underlying premise and specified the seven analytic steps undertaken. For each step, we reviewed industry and academic evidence to test its assumptions and the validity of data applied. Results: We found that, in each step, the Government Model’s assumptions, and the data sources selected, result in underestimates of the scale of digital advertising of unhealthy foods—at least tenfold, if not substantially more. The model’s underlying premise is also problematic, as digital advertising spend data relate poorly to digital advertising exposure, leading to further underestimation of market scale. Conclusion: We conclude that the Government Model very substantially underestimates the impact of digital unhealthy food advertising restrictions on health. This analysis has relevance for global policy and for the impact of regulation on children’s health and well-being.