What we eat is our business, or so we generally believe. We also acknowledge that our individual failures to eat properly have a broader social impact, even if we’re not sure what to do about it. These tensions between individual choice, public well-being, and the wealth and strength of the nation were born in the Enlightenment. While states have always worried about the political implications of famine, only in the eighteenth century did the particularities of what ordinary people ate attract the attention of political theorists: it was in the eighteenth century that everyday eating habits became a matter of state concern. New theories about how to build economically successful states led to new ideas about the relationship between individual diets and national resilience—what we might call food security. Concerned to build healthy populations, eighteenth-century political and economic writers increasingly recommended potatoes as an ideal foodstuff. Potatoes had reached Europe in the sixteenth century, when Spanish colonists introduced this Andean tuber. In the Americas the potato has nourished ordinary people for millennia, and it was ordinary people in Europe and elsewhere who were largely responsible for transforming the potato into the global status that it has today.

The expansion of trade and colonial conquest in the early modern era propelled the potato around the world, but the processes that made it a global staple reflect not only these forces but also the varied circumstances that it encountered on its travels. European colonisers congratulated themselves on bringing the nutritious potato to the supposedly backward inhabitants of Bengal and Botany Bay, and viewed its adoption as an index of the overall level of civilisation attained by locals. For gardeners in Tehran, Māori entrepreneurs in New Zealand, and Bengali villagers, potatoes served other purposes. The transformation of eating habits that followed the global dissemination of American foodstuffs after 1492 reveals the complex interactions between local environments, patterns of agriculture and landholding, commercial structures and existing foodways. The potato’s changing status in China demonstrates this well. For centuries the potato provided an important resource for villagers in peripheral regions, yet was almost invisible to the state. Now it is part of a state strategy to increase food security. This transformation in the potato’s political role coincides with the Chinese state’s embrace of the market economy; vigorous state promotion of potatoes has accordingly emphasised individual choice and personal benefit. In China, as in Europe, capitalism, individualism and personal eating practices are closely intertwined with modern forms of statecraft.

The Enlightenment’s promotion of the potato reflect the close relationship between new ideas about the political importance of everyday eating habits, and new ways of thinking about the economy. Just as Adam Smith recommended that allowing individuals to pursue their own interests would ultimately result in a flourishing economy, so potato-enthusiasts (Smith included) argued that the best way to build a robust population was to empower individuals to make sound dietary choices through campaigns of information and exhortation. Rarely did they suggest that people be obliged to grow or eat potatoes. Such suggestions would have run counter to the entire philosophy that underpinned much enlightened interest in food supply: the new discipline of political economy. This history reveals the eighteenth-century origins of the current, neoliberal, insistence that healthy eating is best understood as a form of individual consumer empowerment that at the same time builds a stronger economy and body politic. Potatoes offer a concrete, everyday example of how this confluence of private interest and public benefit was imagined to occur, at the very moment when these ideas were first theorised.

The potato has nourished ordinary people in the Americas for millennia. Villagers along the Andes grew a great variety of potatoes, which were used in diverse ways to provide year-round nourishment. The Europeans who reached South America’s Pacific coast in the 1530s introduced potatoes to Europe, thereby initiating its global spread. Once in Europe, the potato attracted little attention from representatives of the state. Uninterested as they were in the everyday eating habits of European labourers, few learned writers assessed the novel plant’s potential as a foodstuff for Europeans. Those who did complained that the potato was excessively nourishing and so facilitated laziness. Ordinary people, in contrast, embraced the potato, which possessed a number of advantages over existing foodstuffs. Potatoes can produce a prolific harvest even in poor soil, and make a sustaining meal. Moreover, precisely because states were not interested in the everyday eating habits of poorer folk, it took many decades for the potato to attract the attention of tax-collectors. Potatoes thus allowed peasants and labourers to evade some of the less welcome aspects of state control. It is they who are responsible for the potato’s entry into the European diet.

Potatoes were deeply embedded in nineteenth-century arguments about the merits of capitalism. The potato’s contested status emerges clearly in discussions about Ireland. In the eighteenth century, the potato’s contribution to the Irish diet had been viewed positively, because it enabled population growth. By the mid-nineteenth century it had become both an alarming illustration of the perils of economic autarky and a testament to the evils of capitalism. Commentators on all sides of the debate agreed that the potato encapsulated something of capitalism’s essence. At the same time, as urbanisation and industrialisation advanced, the conviction that the population’s eating habits had a material impact on the body politic only deepened. The new language of nutrition provided a vocabulary for expressing this relationship. From the mid-nineteenth century the potato’s growing importance within the working-class diet attracted the worried attention of nutritionists and statesmen, who condemned the effects of ‘lazy potato blood’ on the working body: the potato’s popularity with workers was blamed for lacklustre economic growth. Talking about potatoes provided a way for working people, scientists, economists and politicians to discuss the enormous changes that were reshaping nineteenth-century Europe in ways that stressed the close connections between economic practices and everyday eating habits.

The potato’s political invisibility ended in the eighteenth century, when it attained unprecedented political prominence. The nourishing qualities that had once drawn criticism began to be viewed more positively. As a result, the potato became the object of intense scientific and political interest across Europe, as officials, local societies, agronomists, priests and many other organisations and individuals promoted potato consumption in word and deed. This extensive, pan-European potato investigation and propaganda resulted in the publication of hundreds of texts extolling the potato’s potential as a superior staple for working people, one whose greater consumption would help ensure the strength and success of the nation. Its popularity reflected the emergence of the new models of political economy and governance that stressed the importance of a healthy, well-nourished population to the power and wealth of the state. Integrating the slower history of the potato’s conquest of European dietaries, discussed in , with its frenetic promotion in the eighteenth century illuminates the central role that food came to play in modern models of statecraft.