In general, quality ratings were reasonably good across the spectrum of categories included in the systematic evidence review; with one exception, the numbers of high- and medium-quality ratings were equal to or greater than the numbers of low ratings for measure quality, causal inference validity, and ecological validity. As anticipated, many results from cross-sectional observational and longitudinal studies were rated low on causal inference validity, and many results from experiments were rated low on ecological validity—typical for the respective designs employed. The research results included in the systematic evidence review were of sufficient quality, diversity, and scope to support several findings about the influence of marketing. The overall finding from the research was that food and beverage marketing influences the preferences and purchase requests of children, influences consumption at least in the short term, is a likely contributor to less healthful diets, and may contribute to negative diet-related health outcomes and risks. The overall finding is drawn from a systematic evidence review of research in three areas, and the findings from these three areas provide more specific information in support of the general finding.
With respect to the specific influence of food and beverage marketing on the precursors (e.g., food preferences and purchase requests) of young people’s diet, a systematic evidence review supported the following findings:
There is strong evidence that television advertising influences the food and beverage preferences of children ages 2–11 years. There is insufficient evidence about its influence on the preferences of teens ages 12–18 years.
There is strong evidence that television advertising influences the food and beverage purchase requests of children ages 2–11 years. There is insufficient evidence about its influence on the purchase requests of teens ages 12–18 years.
There is moderate evidence that television advertising influences the food and beverage beliefs of children ages 2–11 years. There is insufficient evidence about its influence on the beliefs of teens ages 12–18 years.
Given the findings from the systematic evidence review of the influence of marketing on the precursors of diet, and given the evidence from content analyses that the preponderance of television food and beverage advertising relevant to children and youth promotes high-calorie and low-nutrient products, it can be concluded that television advertising influences children to prefer and request high-calorie and low-nutrient foods and beverages.