Using simulation and diets of 16,000 people, scientists discover how to cut your diet’s climate impact in half
Baltimore (June 10, 2019) – Food production is an important contributor to climate change, accounting for about a quarter of carbon emissions globally. According to a study that examined the real-world diets of thousands of people in the U.S., we could greatly reduce the carbon footprint of what we eat by changing just one food each day.
“We found that making one substitution of poultry for beef resulted in an average reduction of dietary greenhouse gases by about a half,” said lead study author Diego Rose, PhD, professor and director of nutrition at Tulane University.
Rose presented the research at Nutrition 2019, the American Society for Nutrition annual meeting, held June 8-11, 2019 in Baltimore.
“To our knowledge, this is the only nationally representative study of the carbon footprint of individually chosen diets in the U.S.,” said Rose. “We hope this research will raise awareness about the role of the food sector in climate change and the sizable impact of a simple dietary change.”
The new study is based on diet information from more than 16,000 participants in the 2005-2010 National Health and Nutrition Examination Survey. A portion of this survey asked participants to recall all the foods they consumed in the previous 24 hours. The researchers used this information to determine which foods had the highest greenhouse gas emissions and to calculate a carbon footprint for each individual diet.
They found that the 10 foods with the highest impacts on the environment were all cuts of beef and that about 20 percent of participants reported consuming one of these high-carbon foods. Using simulation, the researchers calculated a new carbon footprint for each diet by replacing beef with the closest related poultry product. For example, a broiled beef steak was replaced with broiled chicken and ground beef with ground turkey. Each substitution was performed only one time for each person that consumed one of the high-carbon foods.
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Animal foods are known to contribute more to greenhouse gas emissions than plant foods. Ruminant animal foods such as beef and lamb have particularly high carbon footprints because cows and sheep also release methane gas.
“Our simulation showed that you don’t have to give up animal products to improve your carbon footprint,” said Rose. “Just one food substitution brought close to a 50% reduction, on average, in a person’s carbon footprint.”
The researchers plan to expand this research, which focused on dietary greenhouse gas emissions, to include other environmental impacts such as water use.
Although not the subject of this study, they point out that food waste and overeating also increase the carbon footprint of our diet. Thus, in addition to eating low-carbon foods, better meal planning and eating of leftovers can also help reduce carbon footprint.
Diego Rose will present this research on Monday, June 10, from 12:15 – 12:30 p.m. in the Baltimore Convention Center, Room 317 (abstract). Contact the media team for more information or to obtain a free press pass to attend the meeting.
This release may include updated numbers or data that differ from those in the abstract submitted to Nutrition 2019.
Please note that abstracts presented at Nutrition 2019 were evaluated and selected by a committee of experts but have not generally undergone the same peer review process required for publication in a scientific journal. As such, the findings presented should be considered preliminary until a peer-reviewed publication is available.
About Nutrition 2019
Nutrition 2019 is the annual meeting of the American Society for Nutrition held June 8-11, 2019 at the Baltimore Convention Center. It is the national venue for more than 3,600 top researchers, practitioners and other professionals to announce exciting research findings and explore their implications for practice and policy. Scientific symposia address the latest advances in cellular and physiological nutrition and metabolism, clinical and translational nutrition, global and public health, population science, and food science and systems. http://www.nutrition.org/N19 #Nutrition2019
About the American Society for Nutrition (ASN)
ASN is the preeminent professional organization for nutrition research scientists and clinicians around the world. Founded in 1928, the society brings together the top nutrition researchers, medical practitioners, policy makers and industry leaders to advance our knowledge and application of nutrition. ASN publishes four peer-reviewed journals and provides education and professional development opportunities to advance nutrition research, practice and education. http://www.nutrition.org
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