A review of the research literature on communication strategies to influence healthy food choice behaviour supports the view that understanding in this field is seriously impeded by systematic shortcomings, traceable in large part to the diversity of contributions to the literature.

We use the study filtering process and study quality analysis from this literature review to illustrate some fundamental and recurring problems in this body of literature. These problems relate to all stages of the research process: conception, method and study design, analysis, and interpretation. They include the absence or misuse of theoretical justification, deficiencies in the operationalisation of constructs, problems of measurement and statistical analysis, and inappropriate or overly simplistic interpretation of findings.

The studies ranged in type from laboratory-based investigations to public health interventions. The highest quality studies often lacked external validity and focused on mainly immediate effects on food choice behaviour. Intervention studies often involved multiple components in a manner that made it difficult to evaluate the effects of any specific strategy. Evident in a great many studies was a lack of understanding of human behaviour, including the reactivity of human research participants and corresponding implications for both method and the interpretation of data.

In conclusion, whereas many studies address communication strategies and other devices with the aim of influencing food choice behaviour, few do so with the conceptual clarity and methodological and theoretical soundness necessary to provide a guide to practice. In addition, research in this area predictably involves a trade-off between control and external validity. We propose a set of principles to guide methodological decisions in studies designed to inform public health approaches to influence food choice behaviour.