Good for me, good for the planet: Researchers link healthier diet to lower carbon footprint

30 Jan 2023 --- A recent study has found that diets with a lower carbon footprint also have a positive impact on health. Moreover, making simple substitutions in any diet can help collectively lower the environmental impact while improving health and longevity. 

Researchers at the University of California in Los Angeles note that few studies have described planetary benefits alongside human health, which was the goal of this study.

Of the six diets examined, the standard American, keto and paleo diets yielded the highest carbon footprints, while vegan, Mediterranean and climatarian diets exhibited some of the lowest. 

The climatarian diet is defined as a diet that focuses on eating foods that minimize one’s impact on the environment. It emphasizes making informed decisions about the food one eats and choosing low-impact options whenever possible, considering foods’ source, production and transportation.

Innova Market Insights has observed the trend in choosing more food options based on sustainability, naming its number one Top Ten Trend in 2022 “Shared Planet.” 

Plant-based meat analogs have a lower environmental impact than meat, but a higher impact than low-processed meat alternatives like tofu or legumes.Measuring health 
The study, published in the journal Nutrients, acknowledged that there is plenty of conflicting information on the health benefits of certain diets over others, e.g., keto vs. vegan. However, some aspects are generally accepted, such as fresh, whole foods are better for health than highly processed foods – although this too is up for debate. 

Diets heavy in air-freighted or processed foods will likely have higher carbon footprints, write the study’s authors. Processed foods are more likely to be found in vegan and standard American diets, as these have no restrictions on the food category.

In the case of comparing processed imitation meat with red meat, they point out the carbon footprint of plant-based meat is lower. However, the carbon footprints of meat substitutes are still higher than those of whole-food plant-protein alternatives, such as tofu and legumes, as a result of the emissions associated with processing and refrigeration. 

Additionally, diets higher in red meat result in increased saturated fat intake. Whereas the Mediterranean diet, for example, emphasizes the use of healthy unsaturated fats. 

Ruminating over meat consumption 
The most significant factor determining carbon footprint and health impact was the consumption of meat – specifically from ruminant animals, such as cattle, goats and sheep.

Researchers discovered a significant decrease in carbon footprint when swapping out ruminant meat for another animal-based option, such as chicken or pork. 

Specifically, the standard American diet saw a reduction from 8.14 to 2.63 kg CO2-eq, the keto diet saw a reduction from 9.72 to 4.85 kg CO2-eq and the paleo diet saw a reduction from 5.86 to 3.11 kg CO2-eq. 

Consumption of ruminant meat is the most significant factor in determining a diet’s environmental impact, according to a UCLA study.To investigate the impact of meat within the climatarian diet, one meal scenario relied on lower-footprint meat-protein sources while the other scenario maintained a vegetarian diet. 

Removing meat protein resulted in a reduction from 2.54 kg CO2-eq to 1.88 kg CO2-eq. 

A similarly low estimate of 2.17 kg CO2-eq was found in the Mediterranean diet, which inherently emphasizes low-impact meat, such as chicken and fish, over red meat. The vegan diet, as a result of having a complete lack of animal products, was found to have the lowest carbon-footprint estimate of 1.63 kg CO2-eq.

The industry is working to lower the impact of beef, however. In 2019, Cargill launched BeefUp Sustainability with the ambition to reduce 30% of greenhouse gases within its North American beef supply chain by 2030. 

Choosing the right proteins 
Plenty of innovation is underway to find more sustainable alternatives to traditional meat from cows, sheep and other ruminant animals. 

Ruminant meat has an environmental impact that is 20 to 100 times that of plants, they write, whereas non-ruminant animal products, such as milk, eggs, pork, poultry and seafood, have impacts that are 2–25 times higher per kilocalorie of food produced than plants do. 

This trend held even when foods were examined per gram of protein. In terms of its carbon footprint, ruminant livestock directly contributes to 38% of U.S. methane emissions, a greenhouse gas that has 28 times the global warming potential of carbon dioxide. 

Results from the low-impact diets show that meat consumption does not need to be eliminated in order to maintain a diet with a relatively low carbon footprint. 

For instance, substitutions can be made with regard to one’s selection of meats to make the paleo diet more environmentally friendly, such as consuming fish, turkey and chicken as opposed to beef and pork products, which are associated with higher carbon footprints. 

Therefore, a climate-friendly diet is flexible and achievable for the average person, the researchers conclude. 

By Missy Green