The environmental and health impacts of diets and dietary change in 5,500 cities worldwide

The majority of the world’s population live in cities, making food environments in cities an important driver of global diets and the associated health and environmental impacts. Based on dietary data for urban residences and demographic information, we estimated the dietary intake in 5,500 cities with populations over 100 thousand inhabitants. Our estimates indicate that diets in most cities contained greater amounts of foods compared to a country’s average intake in 2020. As a result, cities in most regions were responsible for a larger share of food-related environmental resource use and pollution as their share of population, something that in our impact assessment was mostly driven by increased intake of animal source foods in cities. Cities were also responsible for a large share of diet-related health burden and an outsized share of health-related costs, in line with the generally higher cost levels in cities. Dietary changes to healthier and more sustainable diets could substantially reduce the environmental, health, and cost impacts associated with city diets, but are dependent on consistent policy approaches and support.