Reducing health harms of foods high in fat, sugar or salt: economic modelling – final report

5. Conclusions

5.1 The purpose of this project was to provide an ex-ante analysis of the impact of restricting in-premise all price promotions of discretionary foods on sales. In addition, this project also estimated the impact of restricting the promotion of discretionary food on total calories purchased, after accounting for potential product switching within discretionary food categories and between different food categories.

5.2 In broad terms, two complementary methods were performed to estimate the impact of restricting price promotions and advertising of price promotions on discretionary food categories purchasing: (1) demand analysis using Kantar Worldpanel data and (2) economic choice experiment. As regards the demand analysis, two sets of demands were estimated: first, an inter-category demand model that considered the discretionary food categories as well as other food categories (i.e., non-discretionary) and a non-food category. Second, intra- category demand models, which estimated the effect of the policy for sub-categories within the discretionary food categories. This allowed us to measure the substitution from the discretionary food categories to the other food categories.

5.3 Analyses were conducted to see if there were any differences by Scottish Index of Multiple Deprivation (SIMD); rural-urban classification, household income and life stage.

5.4 The analyses estimated that a policy to restrict all price promotions of discretionary foods would result in a net change of - 613 kcal per capita per week (i.e., -87.6 kcal per capita per day or 4.4 per cent of a daily diet of 2000 kcal) taking account of substitution of different items within food category and between food categories.

5.5 All the nutritional categories showed similar results (calories, sugar, fat, salt), which indicates that restricting promotion of value on discretionary foods is likely to be positive in terms of the purchase/consumption of foods high in fat, sugar and salt. It should be noted that the reduction in nutrients was only partially compensated by the increase in quantities in non-discretionary food and drinks (i.e., other food and drinks).

5.6 With regard to energy and nutrients from the purchases of other food and drink categories, almost all the categories show increases in energy and nutrients except in the case of ready meals, which shows a slight decrease. The highest increases in terms of energy are produced by fats and eggs (96.8 kcal.), which also shows the highest increases in fats (10.4 g.) and saturates (4.2 g.). The highest increases in total sugar come from fruit (3.6 g.) and vegetables (3.0 g.). However, this substitution effect was not enough to offset the gains in terms of overall reduction, particularly energy, fat and sugar intake reduction.

5.7 As regards the results for intra-category analyses, overall, all categories experienced a decrease in total number of kcal. The total decrease in energy in the take home confectionery (348.8 kcal.) was much bigger than in the other categories (85.4 kcal for biscuits, 102.8 kcal for take home savouries, 125.8 kcal ambient cakes and pastries, 28.8 kcal. for total puddings and desserts, 44.8 kcal. for regular soft drinks and 67.9 for edible ices and ice cream).

5.8 As regards the nutrients, sugar was by far where the impact was most heavily felt across the seven discretionary categories, followed by fats and saturated fats and there was almost no impact on salt. In the 'regular soft drinks' category there was only an impact on sugar as this category has very low levels of fat, saturates and salt to start with. Overall, the impact on the different nutrients followed the pattern observed on energy.

5.9 The analysis showed that there was an increase in some of the sub-categories comprising each discretionary food category. Thus, in the take home confectionery category, 'other confectionery' saw an increase in energy, as was the case for crackers and crispbreads in the biscuits category, 'puddings, canned goods and frozen desserts' in the 'total puddings and desserts' category, 'mineral water' in the 'regular soft drinks' category and edible ices and 'premium ice-cream private label' and 'frozen confectionery' in the 'edible ices and ice cream' category. Nevertheless, given the small size of these changes, they did not effect the net decreases in calories, sugars and fats.

5.10 The results from the choice experiment showed that restricting the promotion of price discounts to chocolates, biscuits, and crisps with low/moderate content of fat, sugar, and salt did not significantly affect respondents' choices. However, when comparing with the results from the demand analysis, it is important to consider that the choice experiment analysis focuses on a very specific product instead of products within a category or the entire food and drink choices.

5.11 The overall results indicate that restricting the advertising of all price promotions (i.e., temporary price reduction, Y for £X, Multi-buy and other promotions) has the potential to reduce the number of calories, sugar, saturated fats and sodium (even when considering the substitution effects) for most food groups. However, it should be noted that the results are aggregated across all price promotions. Overall, the modelled impacts may be best viewed as an upper bound on the actual impacts and will depend on what types of promotions for discretionary foods are restricted, as well as other factors, such as future changes in consumer purchasing decisions and retailer behaviour.