摘要：We assessed the evidence for a conceptual “hierarchy of effects” of marketing, to guide understanding of the relationship between children’s exposure to unhealthy food marketing and poor diets and overweight, and drive the research agenda. We reviewed studies assessing the impact of food promotions on children from MEDLINE, Web of Science, ABI Inform, World Health Organization library database, and The Gray Literature Report. We included articles published in English from 2009 to 2013, with earlier articles from a 2009 systematic review. We grouped articles by outcome of exposure and assessed outcomes within a framework depicting a hierarchy of effects of marketing exposures. Evidence supports a logical sequence of effects linking food promotions to individual-level weight outcomes. Future studies should demonstrate the sustained effects of marketing exposure, and exploit variations in exposures to assess differences in outcomes longitudinally. Systematic reviews have shown that food marketing has an effect on children’s food preferences and consumption. 1,2 The lack of evidence directly linking food marketing to children’s weight has proved a barrier to policymakers introducing legislation to limit this practice. 3 Food companies would not invest so heavily in marketing to children and in lobbying against legislation to limit marketing 4 if this did not increase product sales. Nevertheless, evidence is needed to define the mechanisms that underpin marketing’s influence on children’s weight, and the magnitude of these effects. The argument supporting the need to regulate children’s exposure to unhealthy food marketing hinges on 3 pieces of evidence: (1) food marketing not only encourages brand switching within a product category but also attracts new consumers to the broad food group, (2) the majority of promoted foods are energy-dense and nutrient-poor (“unhealthy”), and (3) consumption of promoted foods contributes to excess energy intake that is not compensated for, leading to weight gain and diet-related disease. 4 Recent and complex theories recognize marketing as one form of socialization agent that transmits norms, attitudes, motivations, and behaviors to the learner. 5,6 Social and learning theories posit that exposure to positive media messages cues children to want portrayed products and to model observed behaviors. 5,7 Importantly, these theories suggest that such effects can occur even in the absence of conscious perception of marketing stimuli. 6 Less prominent elements of marketing, and the emotions that are evoked, may be stored in memory and individuals may not consciously acknowledge or believe that a promotion has affected them when it has. 8 The effect of promotions on children’s weight outcomes can be explained by a cascade of effects in which exposure to promotions influences children’s brand awareness, preferences, and consequently their purchases and consumption, 9 similar to the hierarchy of effects underpinning social marketing. 10 Earlier systematic reviews on this topic have variously grouped these outcomes of exposure as potential determinants of behavior (preferences, attitudes, knowledge, beliefs), effects on behavior (purchase, purchase requests, consumption patterns), and diet-related health outcomes (e.g., body weight) 11 ; or as mediators of diet (preferences, beliefs, purchase requests), diet (short-term consumption, usual dietary intake), and diet-related health outcomes. 2 In marketing literature, the relationship between brand awareness and consumption is referred to as “brand equity.” 12 Brand equity is achieved when a brand is highly recognizable and associated with positive attributes. 12 With this review, we aimed to outline a conceptual pathway of effects of how marketing may ultimately influence children’s weight. We also sought to collate information on methods used to measure the impact of food promotions on different levels of effects. Within the term “marketing,” 13 this review specifically focused on food advertising, sponsorships, and sales promotions (collectively referred to as promotions).
