One reason the NHS costs so much is that people do not look after their health. Unhealthy behaviours impose huge costs on society as well as harming the individual. For example, the painful and costly outcome of tooth decay requiring reconstructive surgery in young children is preventable through simple actions by parents, such as supervising tooth brushing and limiting consumption of sugary drinks. Better access to free preventive dental care might help, but this is also a behavioural problem.

Unhealthy behaviours are particularly pervasive among disadvantaged people, who are less responsive to health promotion messages (such as take folic acid before pregnancy or read to your toddler) and less likely to take up free public health services (such as screening programmes). The causes are complex and structural—stressful material conditions and social environments leading to poor mental health and chaotic lifestyles rather than idleness …