A deep learning approach to identify unhealthy advertisements in street view images

Associations between everyday exposure to food marketing and hunger and food craving in adults: An ecological momentary assessment study

Food marketing in television and digital media negatively affects appetitive sensations and eating behaviour in children, but effects are less well understood for outdoor food advertising and adults. This research used Ecological Momentary Assessment (EMA) to explore associations between exposures to food advertising in various contexts (television, digital, outdoors) and adults' hunger and craving for highly advertised food categories. Over one week, participants provided ratings of cravings for types of food (fast food, soft drinks, snacks/confectionery, other) and hunger on a smartphone app up to six times per day when they saw a food advertisement (reactive assessment) and at random intervals (random assessment). Fifty-four participants (70.4 % female; 21.24 ± 3.84 years) provided 1223 assessments (24.7 % reactive, 75.3 % random). Data were analysed in R using multilevel multivariable linear regression models. Participants reported feeling hungrier (X2(1) = 5.85, p = .016, ΔAIC = 3.9) and having stronger cravings (X2(1) = 20.64, p < .001, ΔAIC = 318.6) after seeing food advertisements vs. random assessments. This was driven by greater hunger following television advertising exposure vs. random assessments (β = 1.58, SE = 0.61, p = .010, 95 %CIs 0.38 to 2.78), food advertising via digital devices or outdoors was not associated with hunger. Participants experienced stronger craving after seeing a food advertisement on television (β = 0.52, SE = 0.19, p = .006, 95 %CIs 0.15 to 0.89), outdoors (β = 0.39, SE = 0.12, p < .001, 95 % CIs 0.16 to 0.62) and in digital media (β = 0.36, SE = 0.14, p = .012, 95 % CIs 0.08 to 0.64), vs. random assessments. Cravings were (largely) specific to the advertised food category. EMA can be effective for assessing food marketing associations in adults. The current study provides evidence that food marketing is associated with hunger and craving in adults, which may, with replication, have implications for public health policy.

Revolutionising food advertising monitoring: a machine learning-based method for automated classification of food videos

OBJECTIVE

Food advertising is an important determinant of unhealthy eating. However, analysing a large number of advertisements (ads) to distinguish between food and non-food content is a challenging task. This study aims to develop a machine learning-based method to automatically identify and classify food and non-food ad videos.

DESIGN

Methodological study to develop an algorithm model that prioritises both accuracy and efficiency in monitoring and classifying advertising videos.

SETTING

From a collection of Brazilian television (TV) ads data, we created a database and split it into three sub-databases (i.e. training, validation and test) by extracting frames from ads. Subsequently, the training database was classified using the EfficientNet neural network. The best models and data-balancing strategies were investigated using the validation database. Finally, the test database was used to apply the best model and strategy, and results were verified with field experts.

PARTICIPANTS

The study used 2124 recorded Brazilian TV programming hours from 2018 to 2020. It included 703 food ads and over 20 000 non-food ads, following the protocol developed by the INFORMAS network for monitoring food marketing on TV.

RESULTS

The results showed that the EfficientNet neural network associated with the balanced batches strategy achieved an overall accuracy of 90·5 % on the test database, which represents a reduction of 99·9 % of the time spent on identifying and classifying ads.

CONCLUSIONS

The method studied represents a promising approach for differentiating food and non-food-related video within monitoring food marketing, which has significant practical implications for researchers, public health policymakers, and regulatory bodies.

Towards effective restriction of unhealthy food marketing to children: unlocking the potential of artificial intelligence

The World Health Organization recommends that member states enact policies to limit unhealthy food marketing to children. Chile enacted relatively stringent laws that restrict unhealthy food marketing to children in two phases, beginning in 2016. Dillman-Carpentier and colleagues examined the incremental effectiveness of the first and second phases of Chile's policy in limiting children's exposure to unhealthy food marketing on television relative to pre-policy. Banning advertisements for all 'high-in' products (i.e., those that exceeded thresholds for energy, saturated fats, sugars and/or sodium) during the daytime (phase 2) was more effective in reducing children's exposure to unhealthy food marketing on television than only banning 'high-in' marketing during programs with large child audiences (phase 1). These findings underscore the importance of implementing comprehensive policies that reduce children's exposure to all marketing for unhealthy foods-not simply that which targets them directly-to better protect them from its negative impacts. However, although policies in Chile and other nations have reduced children's exposure to unhealthy food marketing in broadcast media, it is not clear whether such policies have meaningfully reduced children's overall food marketing exposures. This is partly due to the challenges of studying children's digital food marketing exposures, which are an increasingly important source of unhealthy food marketing. To address these methodologic gaps, several research teams are developing artificial intelligence (AI)-enabled systems to assess food marketing to children on digital media and support efforts to monitor compliance with policies that restrict this marketing. These and other AI systems will be essential to comprehensively and systematically study and monitor food marketing to children on digital media internationally and at scale.

Contemporary Approaches for Monitoring Food Marketing to Children to Progress Policy Actions

PURPOSE OF REVIEW

Protecting children from unhealthful food marketing is a global priority policy for improving population diets. Monitoring the nature and extent of children's exposure to this marketing is critical in policy development and implementation. This review summarises contemporary approaches to monitor the nature and extent of food marketing to support policy reform.

RECENT FINDINGS

Monitoring approaches vary depending on the stage of progress of related policy implementation, with resource implications and opportunity costs. Considerations include priority media/settings. marketing techniques assessed, approach to classifying foods, study design and if exposure assessments are based on media content analyses or are estimated or observed based on children's media use. Current evidence is largely limited to high-income countries and focuses on content analyses of TV advertising. Ongoing efforts are needed to support monitoring in low-resource settings and to progress monitoring to better capture children's actual exposures across media and settings.

A scoping review of outdoor food marketing: exposure, power and impacts on eating behaviour and health

BACKGROUND

There is convincing evidence that unhealthy food marketing is extensive on television and in digital media, uses powerful persuasive techniques, and impacts dietary choices and consumption, particularly in children. It is less clear whether this is also the case for outdoor food marketing. This review (i) identifies common criteria used to define outdoor food marketing, (ii) summarises research methodologies used, (iii) identifies available evidence on the exposure, power (i.e. persuasive creative strategies within marketing) and impact of outdoor food marketing on behaviour and health and (iv) identifies knowledge gaps and directions for future research.

METHODS

A systematic search was conducted of Medline (Ovid), Scopus, Science Direct, Proquest, PsycINFO, CINAHL, PubMed, the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials and a number of grey literature sources. Titles and abstracts were screened by one researcher. Relevant full texts were independently checked by two researchers against eligibility criteria.

RESULTS

Fifty-three studies were conducted across twenty-one countries. The majority of studies (n = 39) were conducted in high-income countries. All measured the extent of exposure to outdoor food marketing, twelve also assessed power and three measured impact on behavioural or health outcomes. Criteria used to define outdoor food marketing and methodologies adopted were highly variable across studies. Almost a quarter of advertisements across all studies were for food (mean of 22.1%) and the majority of advertised foods were unhealthy (mean of 63%). The evidence on differences in exposure by SES is heterogenous, which makes it difficult to draw conclusions, however the research suggests that ethnic minority groups have a higher likelihood of exposure to food marketing outdoors. The most frequent persuasive creative strategies were premium offers and use of characters. There was limited evidence on the relationship between exposure to outdoor food marketing and eating behaviour or health outcomes.

CONCLUSIONS

This review highlights the extent of unhealthy outdoor food marketing globally and the powerful methods used within this marketing. There is a need for consistency in defining and measuring outdoor food marketing to enable comparison across time and place. Future research should attempt to measure direct impacts on behaviour and health.

Policies to restrict unhealthy food and beverage advertising in outdoor spaces and on publicly owned assets: A scoping review of the literature

Unhealthy food marketing influences attitudes, preferences, and consumption of unhealthy foods, leading to excess weight gain. Outdoor advertising is highly visible (often displayed on publicly owned assets), but the evidence supporting regulation is unclear. This systematic scoping review of academic and grey literature aimed to (1) describe potential health and economic impacts of implementing government-led policies that restrict unhealthy food advertising in outdoor spaces or on public assets (including studies examining prevalence of advertising, associations with health outcomes and interventional studies); (2) identify and describe existing policies; and (3) identify factors perceived to have influenced policy implementation. Thirty-six academic studies were eligible for inclusion. Most reported on prevalence of unhealthy food advertising, demonstrating high prevalence around schools and in areas of lower socioeconomic position. None examined health and economic impacts of implemented policies. Four jurisdictions were identified with existing regulations; five had broader marketing or consumer protection policies that captured outdoor food marketing. Facilitators of policy implementation included collaboration, effective partnerships, and strong political leadership. Barriers included lobbying by food, media, and advertising industries. Implementation of food marketing policies in outdoor spaces and on public assets is feasible and warranted. Strong coalitions and leadership will be important to drive the policy agenda forward.

Changes in household food and drink purchases following restrictions on the advertisement of high fat, salt, and sugar products across the Transport for London network: A controlled interrupted time series analysis

BACKGROUND

Restricting the advertisement of products with high fat, salt, and sugar (HFSS) content has been recommended as a policy tool to improve diet and tackle obesity, but the impact on HFSS purchasing is unknown. This study aimed to evaluate the impact of HFSS advertising restrictions, implemented across the London (UK) transport network in February 2019, on HFSS purchases.

METHODS AND FINDINGS

Over 5 million take-home food and drink purchases were recorded by 1,970 households (London [intervention], n = 977; North of England [control], n = 993) randomly selected from the Kantar Fast Moving Consumer Goods panel. The intervention and control samples were similar in household characteristics but had small differences in main food shopper sex, socioeconomic position, and body mass index. Using a controlled interrupted time series design, we estimated average weekly household purchases of energy and nutrients from HFSS products in the post-intervention period (44 weeks) compared to a counterfactual constructed from the control and pre-intervention (36 weeks) series. Energy purchased from HFSS products was 6.7% (1,001.0 kcal, 95% CI 456.0 to 1,546.0) lower among intervention households compared to the counterfactual. Relative reductions in purchases of fat (57.9 g, 95% CI 22.1 to 93.7), saturated fat (26.4 g, 95% CI 12.4 to 40.4), and sugar (80.7 g, 95% CI 41.4 to 120.1) from HFSS products were also observed. Energy from chocolate and confectionery purchases was 19.4% (317.9 kcal, 95% CI 200.0 to 435.8) lower among intervention households than for the counterfactual, with corresponding relative reductions in fat (13.1 g, 95% CI 7.5 to 18.8), saturated fat (8.7 g, 95% CI 5.7 to 11.7), sugar (41.4 g, 95% CI 27.4 to 55.4), and salt (0.2 g, 95% CI 0.1 to 0.2) purchased from chocolate and confectionery. Relative reductions are in the context of secular increases in HFSS purchases in both the intervention and control areas, so the policy was associated with attenuated growth of HFSS purchases rather than absolute reduction in HFSS purchases. Study limitations include the lack of out-of-home purchases in our analyses and not being able to assess the sustainability of observed changes beyond 44 weeks.

CONCLUSIONS

This study finds an association between the implementation of restrictions on outdoor HFSS advertising and relative reductions in energy, sugar, and fat purchased from HFSS products. These findings provide support for policies that restrict HFSS advertising as a tool to reduce purchases of HFSS products.

WHAT IS THE PRICE OF OUTDOOR ADVERTISING: A CASE STUDY OF THE CZECH REPUBLIC?

The aim of the paper is to analyze the price of outdoor advertising in various regions of the Czech Republic. The base source of data is the website plakatov.cz, from which the prices of outdoor advertisement in individual regions were obtained. The results show that the prices of outdoor advertisement in the individual regions are the same. The main difference is in how many outdoor advertisements are located in individual regions for the lowest and how many for the highest price. An overview was created, which shows what is the price of outdoor advertisement in each region, how many ads are located in each region and subsequently, the data is displayed using a map. The results show that the cheapest outdoor advertisement is located in the Hradec Králové region. The price of the outdoor advertisement in the Hradec Králové Region is CZK 5,204. On the contrary, the most expensive outdoor advertisement is in Prague. The price of outdoor advertising in Prague is CZK 16,567. Most outdoor advertisements are located in Prague. There are 174 outdoor advertisements in Prague. The lowest number of outdoor advertisements is in the Pardubice and Zlín regions. There are 18 outdoor advertisements in both regions. The difference between outdoor advertisements in the Pardubice and Zlín regions is in their price. While in the Zlín Region outdoor advertising costs CZK 6,466, in the Pardubice Region it costs CZK 12,333. The results are beneficial for people who are interested in outdoor advertising. They are mostly beneficial for outdoor advertising producers to know their standing compared to their competition and other regions.