the results of a systematic evidence review of peer-reviewed literature in the area. They include enough of the technical and analytic detail to support the committee’s findings about the contributions of marketing. Prior to these three sections are several that explain how the systematic evidence review was conducted, and following them are sections that address related elements such as comparison with other recent reviews and needed research. Throughout the chapter, care is taken to consider the role of marketing as one of multiple factors influencing diet and diet-related health.
The chapter begins with a description of the systematic evidence review undertaken to assess the influence of marketing on the diet and diet-related health of children and youth, including how it was organized, the criteria used for including evidence, the dimensions addressed, the coding process, the nature of the evidence examined, and the process used to review this evidence. This is followed by three sections that present the results of the systematic evidence review relevant to three relationships: (1) the relationship between marketing and precursors of diet, (2) the relationship between marketing and diet, and (3) the relationship between marketing and diet-related health. The role of factors with the potential to moderate these three relationships is then discussed. Finally, the systematic evidence review and its findings are considered in relationship to the results of other recent reports, and areas for future research are identified. A summary of the key findings concludes the chapter.
The committee conducted a systematic evidence review in order to investigate and summarize the empirical evidence that is directly relevant to the core question: What is the influence of food and beverage marketing on the diets and diet-related health of children and youth? The committee’s review included 123 published empirical studies identified from a set of nearly 200 in the published literature. Systematic evidence reviews are qualitatively different from meta-analyses or traditional narrative reviews (Petticrew, 2001). Systematic evidence reviews do not involve the statistical synthesis of a set of studies, the technique of meta-analyses, but rather attempt to reduce the inevitable bias from narrative reviews by developing explicit and systematic criteria for study inclusion and for assessing the level of evidentiary support provided by each study. As a result, systematic evidence reviews sometimes include far fewer studies than traditional narrative reviews, but they also typically include more than just randomized controlled trials. For example, this review includes not only many controlled experimental studies, but also many observational studies—both cross-sectional and longitudinal—on the influence of food and beverage marketing on the diets and diet-related health of children and youth.