Is nudge an effective public health strategy to tackle obesity? No.

Over the past decade a common picture on the aetiology of obesity has become largely agreed. After years of competing analyses, most people now accept that obesity is the result of a complex multifactoral interplay. 2 It is not either food intake or physical activity but both. It is not just food oversupply or pricing or domestic culture or food marketing or poor consumer choice or genetic potential. In fact, it is all of these and more. At last, scientific advisers have accepted that they have an analysis to share with politicians and can begin the tortuous process of crafting frameworks for action. So why is the British government quietly breaking with this consensus and putting so much weight behind nudge thinking? Nudge is being presented as a new change mechanism from which public health gain will follow and as a means for avoiding the self defeating, heavy handedness of the state. In fact, it is not that new. The notion that social norms set the framework within which behaviour occurs was articulated by 1930s social science and taken up by US advertising thinkers. What is new, in the form it is championed by Thaler and Sunstein’s book Nudge, is the incorporation of a more psychological view of behaviour into neoclassical economics, a world in which it was previously thought that rational consumers make informed choices that drive markets. It is these free market origins, updated to explain why consumers make the wrong choices, that lie behind the UK coalition government’s enthusiasm for nudge. It dispenses with the complexity of real life contexts and acknowledges only the immediate proximal horizons of consumer choice. At a stroke, policy is reduced to a combination of cognitive and “light” environmental signals, such as location of foods within retail geography. Nudge, along with the responsibility deals, is presented as the alternative to regulation, or, in media jargon, the “nanny state.” Commercial benefit