Designing interventions to change eating behaviours.

Understanding and changing eating behaviours are central to the work of Nutrition Society members working in both research and applied settings. The present paper describes a recently published resource to guide the design of interventions to change behaviour, The Behaviour Change Wheel: A Guide to Designing Interventions (BCW Guide). This is a practical guide to intervention design that brings together recently-developed theory-based tools in behavioural science into a coherent step-by-step design process. It is based on the BCW, a synthesis of nineteen frameworks of behaviour change found in the research literature. The BCW has at its core a model of behaviour known as 'capability', 'opportunity', 'motivation' and 'behaviour'. The model recognises that behaviour is part of an interacting system involving all these components. The BCW identifies different intervention options that can be applied to changing each of the components and policies that can be adopted to deliver those intervention options. The book shows how the BCW links to theory-based frameworks to understand behaviour such as the Theoretical Domains Framework and the recently developed Behaviour Change Technique Taxonomy v1 for specifying intervention content. In essence, it shows how to link what is understood about a given behaviour to types of intervention likely to be effective and then translate this into a locally relevant intervention. In addition, the present paper sets out some principles of intervention design.