This paper brings the Foucauldian concept of "biopower" into dialogue with critical discourse analysis to investigate the increasing use of behavioural economics (or "nudge") in UK health policy. Focusing on the "Change4Life" anti-obesity campaign, the analysis shows how the surrounding order of discourse provides the conditions for individualistic, consumerist policy interventions. Intertextual analysis traces the simplification and distortion of expert obesity knowledge, and multimodal analysis shows how working class lifestyles are pathologised. Through commercially endorsed behaviour change slogans, children are targeted and inculcated into active, self-disciplinary citizenship. The increasing popularity of nudge among state actors lies in its comfortable fit with neoliberal ideology, privatising and individualising responsibility for welfare. I question its claims to "empower" citizens by changing their lifestyle preferences and argue that instead it offers governments a way of ignoring socioeconomic inequality. The 2017 award of the Nobel prize to nudge theorist Richard Thaler signals the extent of its influence in contemporary governance. In this paper I offer a conceptual framework with which to critically engage with it.