If Americans shift their menu to meet the recommendations the U.S. Department of Agriculture (USDA) and the Department of Health and Human Services (HHS), “Dietary Guidelines for Americans, 2010,” dietary greenhouse gas (GHG) emissions could increase 12 percent, according to a study by University of Michigan researchers.
Martin Heller and Gregory Keoleian, of University of Michigan Center for Sustainable Systems, considered 100 foods and the associated GHG emissions that results from their production. They examined the gas emissions associated with their production, as well as the probable effects of shifting Americans to a diet recommended by the U.S. Department of Agriculture-one that recommends that Americans eat more veggies, fruits, whole grains, fat-free and low-fat dairy products and seafood.
They should consume less salt, saturated fat, trans fat, cholesterol, added sugar and refined grains but they don’t explicitly state that Americans should eat less meat.
If Americans decrease their daily caloric intake from 2,534 calories they consume currently on an average to the recommended level of about 2,000 calories while shifting to a healthier diet, greenhouse gas emissions would decrease by only 1 percent, according to Heller and Keoleian.
The paper titled “Greenhouse gas emission estimates of U.S. dietary choices and food loss” was published online on Sept. 5 in the Journal of Industrial Ecology.
“The take-home message is that health and environmental agendas are not aligned in the current dietary recommendations,” Heller said.
The striking point is that while following the recommendations for meat intake would help cut diet-related greenhouse gas emissions, an increased use of dairy products-and to a lesser extent seafood, fruits and vegetables-would have the opposite effect.
This happened basically due to agricultural activities, such as cultivation of crops and livestock for food, contribute significantly to the GHG emissions. Also cattle emit huge amounts of methane as part of their digestion while burping.
In 2010, the United States’ food production lead to about 8 percent of the nation’s greenhouse gas emissions they cite, though those numbers are based on a ‘it takes a gallon of gas to make a pound of beef’ metric that has been widely discredited. The production of both beef cattle and dairy cows is connected to especially high levels of greenhouse gas emissions by vegetarian activists but accurate numbers are difficult to calculate.
The U.S. food system is more attentive towards sustainability, but the researchers say that our environmental and food goals are still not aligned.
The authors also took into account the food wasted that contributes hugely to the annual GHG emissions. They estimate that the annual carbon footprint associated with food wastage is equivalent to that of 33 million vehicles.
To be more sustainable, the researchers advises Americans to reduce the consumption of animal products on a regular basis.