Background Behavioural approaches to designing dietary interventions can over-emphasise the role of reasoned, individual decision-making, neglecting contextual factors, resulting in sub-optimal interventions. This presentation critically analyses the utility of social theory (structuration theory) in the design of dietary interventions.

Methods This study uses the example of designing, implementing and evaluating a school-based dietary intervention underpinned by structuration theory. Structuration theory describes the interplay of societal structures and individual agency that result in social practices and patterns. Qualitative data collected with children (n=124), parents (n=17) and teachers (n=8) were analysed identifying key structures (meanings and normative rules, and resources) as a framework to understand dietary practices. Identified rules and resources provided a basis on which to design an intervention. A process evaluation included interviews with school staff (n=4) and baseline and follow-up data collected from children (n=137). No feedback was returned from parents. The process evaluation examined adherence, fidelity, and acceptability, and provided an indication of effect.

Results Key rules and resources identified in qualitative work were valuing food cooked by family members, cooking inexperience, food misconceptions and rules, lack of food vocabulary, home food provision, school meal and drink provision, curriculum, teacher training, school funding, and national legislation. These findings were translated into an intervention that provided water bottles and water, classroom-based teaching around the curriculum that incorporated the development of cooking skills, a food vocabulary, homework exercises, and teacher training. Areas that could not be addressed included home food provision, school meal provision, school funding and national legislation. The intervention was acceptable to children and largely acceptable to teachers, but timing pressures meant not all exercises could be covered. Improvements were reported around children’s drinks.

Conclusion Intervention components were largely limited to impacting individual level agency. For university-based research teams, structural components remain difficult to modify. Interventions seeking to impact at multiple levels must work with influential stakeholders working at structural levels, who can impact on long term processes. Social theory can help identify structural and individual level opportunities through which to focus dietary interventions, but the small scale approaches that predominate must be re-thought to increase intervention impact.