The 2015 Dietary Guidelines for Americans, newly released by the U.S. Department of Agriculture (USDA) and the U.S. Department of Health and Human Services (HHS), do not include scientific recommendations to improve the environmental sustainability of dietary patterns.
Last year, 49 academic centers, health advocacy groups, and environmental advocacy groups sent a letter urging the agencies to adopt the sustainability recommendations developed by the 2015 Dietary Guidelines Advisory Committee (DGAC). But despite an unprecedented number of public comments—and substantial media coverage of sustainable diets—USDA and HHS decided that sustainability was not within the scope of the guidelines, which are intended to guide nutrition programs nationally.
Some critics, including Dr. Walter Willett of the Harvard T.H. Chan School of Public Health and Dr. Dean Ornish, founder and president of the Preventative Medicine Research Institute, would have liked to see more plant-based recommendations and the inclusion of environmental issues. The justification for excluding sustainability is less than satisfactory to David Katz, founder of the True Health Initiative, who notes that the Dietary Guidelines do include recommendations for physical activity, which is also outside the scope of dietary guidance, but closely related to chronic disease prevention. Furthermore, the Dietary Guidelines identify policymakers as the intended audience of the document, obviating the narrow interpretation of the scope and revealing the need for a more holistic approach to dietary guidance.
Another criticism points out the inconsistency in recommendations for whole foods versus nutrients. Where the guidelines outline opportunities for increased consumption, whole foods such as fruits and vegetables are identified. But where necessary decreases in consumption are outlined, the guidelines steer clear of ruffling industry feathers by identifying individual nutrients—such as saturated fat and added sugars—to limit. Marion Nestle of New York University calls saturated fat a euphemism for meat and added sugar a euphemism for soda and sugar-sweetened beverages. The clarity and consistency of dietary recommendations are undermined by such attempts to avoid identification of unhealthy foods, according to Nestle.
Notably missing are the DGAC’s recommendations to limit red meat and processed meats—a suggestion which would improve both human and planetary health, according to the expert committee. Reducing meat consumption is a key aspect of reducing climate change emissions, according to new research from the Johns Hopkins Center for a Livable Future.
Aside from sustainability recommendations, the Dietary Guidelines did preserve some of the other science-based suggestions for changes. The cholesterol limit was scrapped, and a recommendation to limit added sugars to 10 percent of total calories was added. The restriction on sodium also shifted from 1,500 mg per day to 2,300 mg per day, a target still overshot by most American adults.
According to Dr. Parke Wilde of the Tufts University Friedman School of Nutrition Science and Policy, “departments are under intense pressure from Congress, and an official document of this type necessarily reflects a broad and inclusive area of common ground.” Others interpret the looser language of the Dietary Guidelines—as compared to the scientific report—as a lost opportunity to fight industry influence.
Katz writes that the guidelines are “a betrayal of the diligent work of nutrition scientists, and a willful sacrifice of public health on the altar of profit for well-organized special interests.”
The silver lining—according to Katz—is the clarity and quality of DGAC’s original scientific report. Policymakers would do better to consult DGAC’s report, which upholds scientific principles over politics while consumers will have to turn elsewhere for information on the intricate relationships between diet and ecological sustainability.