A comprehensive set of interventions needs to employ the full set of mechanisms for changing physical activity and nutritional behaviour. Education about the risks of obesity is important; so is taking personal responsibility for one’s health, fitness, and weight. But all the evidence shows that these are not sufficient on their own to offset the body’s desire to eat that has been honed over millennia of evolution. People need help and that means a change in the environment in which they are making choices – change such as reduced standard portion sizes, changing marketing practices, and restructuring cities and educational establishments to make it easier for people to exercise.
Our analysis for the UK suggests that almost all the interventions identified are cost-effective for society – savings on healthcare costs and higher productivity could outweigh the direct investment required to deliver the intervention when assessed over the full lifetime of the target population. An integrated program to reverse rising obesity could save the National Health Service about $1.2 billion a year. It is important to note that not all of the interventions are cost-effective for the specific stakeholder delivering them. Sometimes the return on investment lands elsewhere in the economy, the benefits going to households or to healthcare systems, for instance. This misalignment of economic incentives is one of the major challenges inhibiting concerted coordinated action on obesity.