'Are healthier diets always better for the environment?'

For populations facing dietary deficits, better nutrition may require larger and more diverse supplies of fruit, vegetables and foods rich in high-quality protein. Producing and distributing these foods may increase greenhouse gas emissions, water demand and nutrient pollution, or transfer some of these pressures from consumers to distant producing regions.

This presentation will examine when and where such shifts occur and how they might be limited. Drawing on modelling studies, it will compare the environmental consequences of dietary transitions across countries and population groups, identifying where healthier diets may create additional resource pressures. It will then use two Chinese case studies to test potential supply-side responses: urban agriculture to meet part of the demand for vegetables, and aquaculture to supply high-quality protein. The first examines the use of underused urban spaces for vegetable production, the allocation of rooftops between food and solar energy, and circular nutrient management. The second assesses how environmental impacts vary among aquatic food categories, production systems, and along their full supply chains. Together, these cases test whether supply-side innovation can offset the additional pressures of dietary improvement rather than simply move them elsewhere. The presentation will argue that the environmental outcomes depend not only on what people eat, but also on how, where and when their food is produced. The insights are essential for sustainable, equitable, and healthy dietary transitions in China and other developing regions with nutrition deficiencies.