Agricultural policies, food and public health.

What and how much we eat and drink has a significant influence on our health. this is evident in the epidemic of obesity sweeping across developed and developing nations alike, bringing in its wake a range of diseases including diabetes, coronary heart disease and some cancers. one main cause of this is a change in diet that has directly affected our health and well-being. For more than a century, Western governments have invested heavily in agricultural research and infrastructure with the aim of providing sufficient, affordable animal products and some basic cash crops. accordingly, Western diets have shifted over the past century, in particular during the period following the Second World War, to include more animal-sourced foods—such as meat, poultry, dairy products, seafood and eggs—as well as more refined carbohydrates—that is, caloric sweeteners from a range of food crops including sugar cane, sugar beets and corn. During this same period, however, we have begun to realize that a healthy diet actually requires fewer animal products and refined carbohydrates and more vegetables, fruits, beans and whole grains. redressing this balance is a complex task requiring not only a shift in agricultural investment and policy, but also changes in social preferences that have developed over decades, in part due to the relative cheapness of animal-sourced foods. Many groups offer specialized perspectives on food; ‘locavores’ and the slow food movement, public health advocates who want to ban sugar-sweetened beverages and other ‘junk’ or low-nutritional-value food, economists, agricultural scientists and other experts. My perspective as a global nutrition scientist and human-resource economist is to analyse the forces that have shaped our food supply in order to understand what we habitually eat and drink today. this could help to understand what it might take to improve imbalanced diets and recapture earlier and healthier eating patterns. it is therefore instructive to look at food, agriculture and diets from a historical perspective, as our health requirements and our understanding of the role of diet in health is different from earlier periods.