A systematic review of the influences of food store product placement on dietary-related outcomes

Context: Product placement strategies have been used to influence customers' food purchases in food stores for some time; however, assessment of the evidence that these techniques can limit unhealthy, and promote healthy, food choices has not been completed.

Objective: This systematic review aimed to determine how product placement strategies, availability, and positioning, in physical retail food stores located in high-income countries, influence dietary-related behaviors.

Data sources: From a search of 9 databases, 38 articles, 17 observational studies, and 22 intervention studies met the study inclusion criteria.

Data extraction: Two reviewers independently extracted data relating to study design, study population, exposures, outcomes, and key results. Each study was also assessed for risk of bias in relation to the research question.

Data analysis: Meta-analysis was not possible owing to heterogeneous study designs and outcomes. As recommended by Cochrane, results were synthesized in effect direction plots using a vote-counting technique which recorded the direction of effect and significance level according to the expected relationship for health improvement.

Conclusions: The majority of studies showed that greater availability and more prominent positioning of healthy foods, or reduced availability and less prominent positioning of unhealthy foods, related to better dietary-related behaviors. A large number of results, however, were nonsignificant, which likely reflects the methodological difficulties inherent in this research field. Adequately powered intervention studies that test both the independent and additive effects of availability and positioning strategies are needed.

Systematic review registration: PROSPERO registration no. 42016048826.