An unhealthy diet is the leading risk factor for the growing, global burdens of obesity and non-communicable disease, which disproportionately affect individuals in lower socioeconomic positions. As we attempt to understand the ‘causes of the causes’, that drive unhealthy eating, naturalistic and in-depth qualitative inquiry is required to ‘give voice’ to every day citizens by exploring their perspectives and life experiences. Whilst multiple studies have attempted to achieve this, to date there has been no collective synthesis or analysis of these studies. This is essential to advance our understanding and guide the identification and implementation of effective interventions to improve population diets. This study aims to systematically review the literature to identify factors perceived to influence healthy eating among adults and whether these differ across the socioeconomic gradient. The review protocol has been registered in PROSPERO (CRD42017065243).
Relevant qualitative studies were searched for in four academic databases which retrieved a total of 9,895 records. Grey literature and reference list searches were also conducted and 33 eligible studies were identified. The studies represented a combined sample of 1451 adults with 76% in community settings, 48% in the United States and over one third in low socioeconomic groups. Interpretive analysis of the qualitative findings is being conducted according to the seven steps of meta-ethnographic synthesis, described by Noblit and Hare (1988). Preliminary findings indicate that cost is the most frequently reported barrier to healthy eating (85% of studies), with all studies targeted at low socioeconomic participants alluding to this theme. Perceptions regarding social environments, knowledge and skills, time constraints, effort, health and food availability were also common factors influencing healthful eating. These findings will enhance our knowledge of where and how to intervene to improve population diets and reduce the burden of obesity and non-communicable disease across all socioeconomic groups.