It is widely acknowledged that adopting a healthy lifestyle, including healthy eating, not smoking, limiting alcohol intake and being physically active, is essential in reducing premature morbidity and mortality. For example, smoking remains the greatest single cause of premature death, causing more than 19% of all new cancer cases (Parkin et al 2011). It has been suggested that around 80% of heart disease, stroke and type 2 diabetes (World Health Organization (WHO) (2008), and 43% of cancer cases (Parkin et al 2011) could be avoided by changing lifestyle. The King’s Fund (Boyce et al 2008) estimated that unhealthy behaviours cost the NHS £6 billion per year and treatment of obesity alone costs the NHS £0.5 billion per year (National Audit Office 2001).