Environmental Impacts and Nutritional Quality of Rapidly Changing Diets

When millions of people drastically change the types of food they eat over a short period of time, how does it impact the planet? A team of researchers from the University of Maryland Department of Geographical Sciences sought to answer this and other questions about the relationship between health and the environment by studying a recent shift in nutritional habits in China.

Between 1997 and 2011, the Chinese changed their sources of calories considerably by replacing starchy foods with more meat and cooking oil and integrating more dairy and produce. The UMD research team assessed the nutritional intake of more than 21,500 individuals living in nine Chinese provinces during that time period to quantify their environmental footprints. Their findings were published in Nature Sustainability March 12.

“In China, as well as many other developing countries, the dietary transition from starchy food-based diets to more animal-based products has been adding new complexity to the environment-nutrition nexus,” explained UMD Professor of Geographical Sciences Klaus Hubacek, one of the study’s lead authors. “Such trends can help improve or increase dietary health risks but also potentially contribute to growing environmental problems.”

Corresponding author and Associate Professor Giovanni Baiocchi added; “By taking a closer look at what occurred in China, we hope to better understand and predict what impacts will be in other fast-developing areas of the world in order to look for win-win policy solutions that can improve both health and environmental sustainability.”

The research team’s analysis revealed that an increased consumption of meat, cooking oil and other non-starchy foods in China led to an overall increase in greenhouse gas emissions, water consumption and land appropriation. The growth of meat intake was the most important contributor to environmental impacts, the researchers note. On average, individuals in the study consumed at least 100% more meat than needed to meet daily dietary requirements, while middle-and high-income groups in urban areas consumed as much as 300% more.

The global food system consumes more than 70% of the world’s surface and groundwater, occupies 37% of the Earth’s landmass and emits as much as one-quarter of total greenhouse gas emissions. Study authors say balancing nutritional health with environmental responsibility will take an integrative approach that considers the trade-offs between public health and the planet.

“So far, discussion has mainly focused on greenhouse gas emissions related to dietary change but we need to be looking at water consumption, ecological footprints and land occupation all at the same time,” said Pan He, a UMD research associate and lead author of the Nature Sustainability paper. “Our results demonstrate that food policies should incorporate consideration of environmental sustainability to guide consumer choice, while environmental regulations should be developed based on food demand that can support healthy lives.”

Vegetables on a cutting board with text "Our Changing Foodprint."