A new study by researchers at University of California Santa Barbara (UCSB) suggests a “healthier diet” in the United States could reduce greenhouse gas emissions in both the food and health care systems. Its results echo the findings of other recent studies, indicating diet change could play a large role in climate change mitigation.
The researchers developed a model to analyze the effect adopting a healthier diet has on the risk of disease, health care costs, and greenhouse gas emissions. To do so, they used published data from meta-analyses on the effect of foods on diseases. They then used life cycle assessment data from the foods that changed in the healthier diet to evaluate the diets’ impact on greenhouse gas emissions in the food system.
To analyze the effect on the health care system, the researchers estimated the change in risk of diabetes, colorectal cancer, and coronary heart disease as a result of a healthier diet and its influence on the total costs and greenhouse gas emissions of the system.
“People have looked at what effect diets have both on climate and on health,” says the study’s director, David Cleveland, in a UCSB press release. “But they’ve never examined the potential to mitigate climate change through the food system and the health care system together.”
According to the study’s results, adopting a healthier diet has the potential to reduce the risk of coronary heart disease, colorectal cancer, and Type-2 diabetes by 20 to 45 percent. On the health care side, making the switch would reduce the cost of the system by US$77 billion to US$93 billion per year. Additionally, greenhouse gas emissions in the health care system would be reduced by 69 to 84 kilograms of CO2 per capita per year and 153 to 742 kilograms per capita per year in the food system.
To create the healthier diet model, the researches changed the sources of half the calories in a standard 2,000 calorie per day U.S. diet, reducing the number of red and processed meats and doubling the amount of fruits and vegetables. Beans and peas were substituted as an alternative protein source. To err on the conservative side, the diet model did not eliminate added sugars, fish, dairy, eggs, or non-red meats.
“Just changing half of the diet and including only some of the diseases associated with diets, we found a huge effect,” says Cleveland. “That means that there is enormous potential for our food choices to have positive effects on our environment as well as on our health and our health care costs.”
The study also reports the resulting emissions reductions generated by the model meet 6 to 23 percent of the U.S. Climate Action Plan’s 2020 target of reducing 2005 GHG levels by 17 percent, suggesting diet change should be more greatly explored in future food, health, and climate change mitigation policies.
