Effect of restrictions on television food advertising to children on exposure to advertisements for less healthy foods: a repeat cross-sectional study

Abstract

BackgroundThe prevalence of overweight and obesity has increased rapidly in recent years. Consumption of an unhealthy diet is a key contributor to development of overweight and obesity. Several systematic reviews have concluded that food advertising has an effect on children's food preferences, purchasing requests, and consumption. There is also growing evidence that food marketing affects adults' food consumption. Because most food advertising focuses on less healthy products, advertising is likely to play an important part in the development and maintenance of overweight and obesity. In 2007, new scheduling restrictions on television food advertising to children were announced in the UK. The aim of the restrictions was to “reduce significantly the exposure of children under 16 to high fat, salt or sugar (HFSS) advertising”. The UK was the first territory worldwide to introduce statutory scheduling restrictions of food advertisements to children. As such, the effects of such restrictions were unknown. Our aim was to assess the effect of the scheduling restrictions on relative exposure to HFSS food advertising among all viewers and among child television viewers, as well as adherence to the restrictions. MethodsWe undertook two cross-sectional studies of all advertisements broadcast in one region of the UK during 1-week periods—the first (week 1) 6 months before the restrictions were introduced, and the second (week 2) 6 months after. Data for what products were advertised were linked to data for how many people overall, and how many children aged 4–15 years, watched each advertisement. Both sets of data were provided by an audience research bureau and derived from national viewing figures. Nutritional content of foods advertised was added to the dataset and used to calculate HFSS status using the UK Food Standards Agency's nutrient profiling model. Relative exposure was calculated as the proportion of all advertising person-minute-views (PMV) that were for HFSS foods. Findings1 672 417 advertising PMV were included in the analysis. 14·6% of advertising PMV were for food and 51·1% of these were for HFSS food. Relative exposure of all viewers to HFSS food advertising increased between study weeks 1 and 2 (odds ratio [OR] 1·54, 99% CI 1·51–1·57). Exposure of children to HFSS food advertising did not change between study weeks 1 and 2 (OR 1·05, 0·99–1·12). There was almost universal adherence to the restrictions. InterpretationDespite good adherence to the new scheduling restrictions, their introduction was not associated with a change in relative exposure of children to HFSS advertising. Their introduction was associated with an increase in relative exposure of all viewers to HFSS advertising. Stronger restrictions targeting a wider range of advertisements are necessary to reduce exposure of children to advertising of less healthy foods. Limitations include the repeat cross-sectional approach, which cannot establish causation; the short, 1-week, study periods, which might not be representative of all advertising; and the reliance on national viewing figures, which are calculated from fairly small, although demographically representative, panels. FundingNational Prevention Research Initiative, with the support of the British Heart Foundation (BHF), Cancer Research UK; Department of Health, Diabetes UK, Economic and Social Research Council, Food Standards Agency, Medical Research Council (MRC), Health and Social Care Research and Development Office for Northern Ireland, Chief Scientist Office, Scottish Government Health Directorate, The Stroke Association, Welsh Assembly Government, and World Cancer Research Fund. The award was administered by the MRC (G0701873). JA, AJA, and MW receive salary support from Fuse–the Centre for Translational Research in Public Health, which is funded by the BHF, Cancer Research UK, Economic and Social Research Council, MRC, and the National Institute for Health Research (NIHR), under the auspices of the UK Clinical Research Collaboration. At the time of funding, AJA received salary support from an NIHR Public Health Career Scientist fellowship.