Space-time analysis of unhealthy food advertising: New Zealand children’s exposure and health policy options

Abstract

Summary Reducing children’s exposure to unhealthy food advertising is an accepted strategy to end childhood obesity. This study aimed to (i) measure children’s space-time exposures to unhealthy food advertising in public outdoor spaces, using GPS and wearable cameras; and (ii) test effectiveness of banning options. We compiled data (collected July 2014—June 2015) on 138 12-year-old children in Wellington, New Zealand, using wearable cameras and GPS devices worn over 4 days. In 2017–18, we linked 59 150 images taken in public outdoor spaces to GPS data. Of these, 1631 contained unhealthy food advertising exposures, defined as ≥50% of an advertisement observed in each image. We examined spatial patterns using kernel density mapping and graphed space-time trends. We interpolated a kriged exposure rate across Wellington to estimate exposure reductions for potential bans. Children were exposed to 7.4 (95% CI 7.0–7.8) unhealthy food advertisements/hour spent in outdoor public spaces. Exposures occurred in shopping centres, residential areas and sports facilities, commonly involving fast food, sugary drinks and ice cream. Peak exposure times were weekend afternoons/evenings and weekdays before/after school. In Wellington, we estimated that banning such advertising within 400 m of playgrounds would yield a 33% reduction in exposure, followed by in residential areas (27%), within 400 m of schools (25%), and 50% for a ban combining all above. This work documents the extent of children’s exposure to unhealthy food advertising and the potential impact of bans. Given the ubiquity of advertising in public spaces, this New Zealand research offers innovative methods and findings likely relevant in other jurisdictions.

An analysis of food and beverage advertising on bus shelters in a deprived area of Northern England

“…protein, vegetables and fibre) and offsets these against the undesirable nutrients, which can lead to some classifications that appear counterintuitive (such as McDonalds fries being healthy). Foods not permitted by the WHO Euro NPM have consistently made up a majority of food advertisements outdoors, with previous studies reporting 50•2 % (23) and 89•2 % (55) , and, in the present study, 79•5 %.…”

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

“…Of the 36 included studies, 28 reported on the prevalence of unhealthy advertising in outdoor spaces or on publicly owned assets 33–60 ; two reported associations between outdoor marketing and consumption of unhealthy food 6,61 ; one reported associations between outdoor advertising and the school food environment 58 ; one reported outdoor advertising and neighborhood level obesity rates 62 ; two reported on policy options for regulating unhealthy food marketing in outdoor environments 63,64 ; two reported on public opinions towards marketing regulation 65,66 ; and one study reported an evaluation of Chile’s Law of Food Labeling and Advertising 67 . A detailed description of all included studies from the academic literature is reported in Table S1.…”

“…Twelve studies reported on outdoor advertising specifically in areas surrounding schools. These studies, undertaken in various countries (Australia, 44,52,53 New Zealand, 39,42,46,49,58 Canada, 57 the USA, 41,43 and Manila, The Philippines, and Ulaanbaatar, Mongolia 45 ), consistently showed that unhealthy food and beverage advertising is prevalent in areas around schools. For example, one Australian study of advertisements within a 500-m radius of primary schools in Sydney and Wollongong found that 80% of food and beverage advertisements were promoting unhealthy food, beverages and alcohol.…”

Child-centered food systems: Reorienting food systems towards healthy diets for children

“…Overall, children tend to be neglected in these studies (Ravensbergen et al, 2016). Recent exceptions include research in New Zealand using GPS and wearable cameras to measure children's space-time exposures to unhealthy food advertising in public outdoor spaces and Google street view to identify the types of advertising across the built environment (Liu et al, 2019;Egli et al, 2019); and in Beirut and Tunis, testing out wearable cameras as a measure of exposure to obesogenic environments (Semaan et al, 2020). An earlier study in Canada used activity-travel log approach to identify children's "activity spaces" beginning and ultimately ending at home in relation to fast food outlet exposure (Ravensbergen et al, 2016).…”