The relationship between nutrition and behaviour is bi-directional in nature, with nutritional factors able to affect activity and disposition, and behavior impacting diet and food intake. This book reviews these links, starting with their complex neurobiological basis, such as in the case of folate deficiency and cognitive decline. It also illustrates how behaviour may determine nutritional choices or status through peer modelling and poor dietary habits. Micronutrients and eating disorders are then critically addressed, with a review of current research methods and results, before extra-nutritional influencers on behaviour such as caffeine, herbal supplements and alcohol are discussed in the final section.