During the last three decades, obesity has emerged as a big public health issue in affluent societies. A number of academic and policy approaches have been taken, none of which has been very effective. Most of the academic research, whether biological, epidemiological, social-scientific, or inthe humanities, has focused on the individual, and on his or her response to external incentives.The point of departure taken here is that institutions matter a great deal too, and especially the normative environment of the nation state. In brief, the argument is that obesity is a response to stress, and that some types of welfare regimes are more stressful than others. English-speakingmarket-liberal societies have higher levels of obesity, and also higher levels of labour and product market competition, which induce uncertainty and anxiety. The studies presented here investigate this hypothesis, utilising a variety of disciplines, and the concluding contribution by the editorspresents strong statistical evidence for its validity at the aggregate level. The hypothesis has an important bearing on public health policy and, indirectly, on economic policy more generally. It indicates that important drivers of obesity arise from the interaction between the external 'shock' offalling food prices and the enduring normative assumptions that govern society as a whole.If obesity is determined in part by inflexible norms and institutions, it may not be easy to counter it by focused interventions. Distinctive societal policy norms like an attachment to individualism (which national communities embrace with some conviction) may have harmful social spillovers whichare rarely taken into account.