The U.S. government’s guidelines to healthy eating are at odds with a healthy environment, according to a new report by researchers at the University of Michigan. In fact, it says, agricultural production of recommended foods could increase the emissions of greenhouse gases.
The study by Martin Heller and Gregory Keoleian of the university’s Center for Sustainable Systems focused on emissions from the production of about 100 foods, as well as the likely effects of persuading Americans to adhere more closely to a diet recommended by the U.S. Department of Agriculture.
If the population accepted the USDA’s “Dietary Guidelines for Americans, 2010,” but consumed the same number of calories they do now, about 2,500 a day, greenhouse gas emissions would rise by 12 percent. If Americans cut their daily caloric intake to 2,000, as recommended by the USDA, emissions would rise by 11 percent, according to their report 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 concluded. In an interview with the university’s news service, he also notes that the publication of the paper comes at a time when the USDA Dietary Guidelines Advisory Committee is considering aligning food sustainability with dietary recommendations.
The 2010 dietary guidelines recommend that Americans shift to what today is considered a healthy diet centering on vegetables, grains and fruits, low- and non-fat dairy, and seafood, and eat less salt, saturated and trans fats, cholesterol, refined grains and sugar.
The report's appendix recommends limits on certain foods, including meat. Heller and Keoleian agree that a decline in meat consumption would help cut emissions related to diet, but their research found that increased consumption of dairy products and even seafood, fruits and vegetables would actually increase diet-related emissions.
In 2010, 8 percent of U.S. greenhouse gas emissions came from food production, most of it from animal-based foods, particularly cattle. That’s because cows need enormous amounts of plant-based feed to compensate for their inability to convert the feed efficiently into muscle and milk.
Add to that, cattle feed is sown and harvested with farm equipment that usually burns fossil fuels, and its growth often is enhanced with substances including fertilizers, which require a lot of energy to produce. Plus, cattle produce a lot of methane, a potent greenhouse gas.
So while beef makes up only 4 percent of the weight of available food in the United States, the report says, it’s responsible for 36 percent of the country’s greenhouse gases. Heller and Keoleian agree that there must be a drop in meat consumption, which would lead to a drop in meat production, and therefore a drop in greenhouse gas emissions.
But a simultaneous increase in consumption of dairy, vegetables and fruits would increase these emissions, they conclude, because of the energy required to produce them.
By Andy Tully of Oilprice.com
Andy Tully is a veteran news reporter who is now the news editor for Oilprice.com