When it comes to changing human dietary behaviour, it is increasingly recognised that knowledge is not enough. Nevertheless, the majority of nutritional interventions designed to improve dietary quality are educational in nature and are predicated on the assumption that eating behaviour is primarily the product of a conscious and rational decision-making processes. The study of human food choice challenges the adequacy of this assumption and questions the sufficiency of knowledge-based interventions. The determinants of food choice are complex and are shaped by biological, developmental, social, cultural and economic forces. This article presents a selection of food choice research relevant to the development of healthy eating practices and illustrates how interventions based on psychological and social influences could lead to improved outcomes.