- A new study from the University of Leeds in the UK shows that a healthy diet may reduce greenhouse gas emissions.
- Lower red meat, sugary drinks and snacks damage the ecosystem less, say the scientists.
- They conclude that governments should promote plant-based diets for personal and global health.
More than a third of worldwide GHG emissions are attributed to food production, processing, and packaging.
However, most studies on the impact of dietary behaviors on the environment have concentrated on a small number of broad food groups. A new study sought to give more detailed information on the environmental impact of food production.
“To go beyond general recommendations at the population level to particular advise suited to the individual,” the authors write in the new article, “measures of environmental sustainability applied to a full variety of specific food items at a more granular level are required.”
Dr. Holly Rippin, Ph.D., and her colleagues looked into the GHG emissions of over 3,000 different foods. The researchers found that healthier diets are more environmentally friendly after tying these findings to a diet survey.
Their findings were published in the peer-reviewed journal PLOS One.
Choosing parameters
The U.K. Composition of Foods Integrated Dataset now includes GHG emissions from particular foods, thanks to Dr. Rippin and her team. They were able to calculate GHG emissions for individual diets as a result of this.
The researchers looked at emissions based on eating patterns, demographics, and World Health Organization (WHO) nutrient intake recommendations (RNIs).
“We selected to report on GHG emissions rather than land and water use, or acidifying and eutrophicating emissions because this is where links between health and environmental gains have previously emerged strongest,” the researchers explained.
Linking dietary data
Nutritools myfood24 is a web-based food diary that allows you to track and analyze your nutritional consumption.
The current study included a validation cohort of 212 participants who used the myfood24 application and a 24-hour recall conducted by an interviewer.
On one to three occasions, around two weeks apart, the researchers compared the subjects’ results to reference measures from biomarkers and RNIs.
Largest dietary GHG sources
Meat accounted for 32 percent of overall diet-related GHG emissions, according to the study.
15 percent of emissions were attributed to beverages such as coffee, tea, and alcoholic beverages, while 14 percent were attributed to dairy. Cake, cookies, and candies may have accounted for 8% of total GHG emissions.
The study also discovered that men’s diets were related with 41% higher GHG emissions than women’s diets. This differential was “driven by disparities in meat eating and, to a lesser extent, by GHG emissions from drinks,” according to the scientists.
Furthermore, nonvegetarian diets produced 59 percent more greenhouse gas emissions than vegetarian diets.
The researchers also discovered that people who ate meals high in saturated fat and sodium but low in carbs had increased GHG emissions.
Diets that met the RNIs had less meat and produced fewer GHG emissions, such as those with lower saturated fat and sodium intake.
Efforts to optimize diets
Nutritionally optimized diets, according to Dr. Rippin and her co-authors, can have a lower carbon impact. They do, however, acknowledge that trade-offs are unavoidable.
The Eatwell Guide in the United Kingdom, for example, may reduce GHG emissions while increasing water use.
Dr. Diego Rose, Ph.D., MPH, a professor and director of Nutrition at Tulane University School of Public Health & Tropical Medicine in New Orleans, spoke with Medical News Today about the study.
Dr. Rose was asked by MNT if the UK’s objective of lowering GHG emissions by 80% by 2050 is feasible. He replied:
“We need major changes across all sectors to address our climate problem, and that includes the food sector. As for the possibility of accomplishing this, well, I’m an optimist, so, yes, I do think this is possible. It’s not just about the production side, though. Changes in consumer practices are needed, both in terms of the types of food chosen and in terms of the amount of food wasted.”
Dr. Rose, on the other hand, isn’t convinced that taxing foods is the best way to reduce red meat consumption, as the study authors advise. He indicated, “
“Instituting consumer food taxes can be challenging because of the political environment, so it will depend on the context. Many people don’t understand the connection between dietary choice and environmental impact, so before thinking about taxes, it makes more sense to think about consumer education, dietary guidance, or food labeling.”
A different point of view
Defending Beef is written by Nicolette Hahn Niman, a rancher and former environmental lawyer. She claims that it is industrialization, not red meat, that poses the greatest harm to human and environmental health.
Niman claimed in a September 2021 podcast that the Earth has the answers to attaining sustainable agriculture and diets:
“We need […] to look at nature to get the solutions. That doesn’t mean that we throw out technology. We also need to look at all the emerging science around these things, dietary issues and soil health, and carbon sequestration. There’s a great deal of benefit to a lot of research that’s happening around the world. But we also have to look at and learn the wisdom that humans and animals have had for forever.”
“We need to understand the landscape function,” she continued. “What was this Earth meant to do whatever area we are in? How was it meant to function, and how will it ecologically function optimally? […] When we do that, we will be creating healthy diets and also a healthy planet.”
Limitations of the research
Dr. Rippin and her colleagues are well aware of the study’s shortcomings. For example, only 212 people in the cohort reported food consumption for a maximum of three days.
Furthermore, while this study only looked at greenhouse gas emissions, “many environmental implications must be considered to ensure cohesiveness within the food production system.” Although almonds and olive oil have a modest impact on GHG emissions, they utilize a lot of water.”
It’s difficult to grasp the connections between what we consume and how it affects the environment. Understanding it necessitates a thorough examination of all factors, including land use, packaging manufacturing, the distance traveled by food to reach our dinner plates, and everything in between.
This study contributes to the development of a clearer picture, but much more research is required to fill in the gaps and examine how all of the moving parts interact.
