Prevalence of healthy and unhealthy food and beverage price promotions and their potential influence on shopper purchasing behaviour: A systematic review of the literature.

Policies to restrict unhealthy food and beverage price promotions have been recommended, as part of a broader strategy to reduce obesity, but little evidence underpins such recommendations. We aimed to synthesize the literature on the prevalence of healthy and unhealthy food and beverage price promotions and their potential influence on purchasing behaviour. Eight scientific databases (covering health, business, and marketing) and grey literature were systematically searched using search terms related to "food and beverage price promotions" up until July 2019. Articles were included if they examined prevalence of, and/or consumer response to, food and non-alcoholic beverage price promotions, from a nutritional perspective. Of the 16 included studies, eight examined the prevalence of price promotions and eight examined the potential influence of price promotions on purchasing behaviour. Seven of the "prevalence" studies found that price promotions were more common for unhealthy foods and beverages. Seven "influence" studies found a greater proportion of price-promoted purchases were for unhealthy compared with healthy products. Policies that reduce the prevalence and/or influence of price promotions on unhealthy foods and beverages may shift consumer purchasing away from unhealthy foods and beverages. Empirical studies are required to better understand how consumers and industry may respond to such policies.