Science commentary: It makes sense to include sustainability in dietary guidelines

In a commentary today for the journal Science, several colleagues and I explain why we think it is fine to include considerations of environmental sustainability within the scope of the U.S. Dietary Guidelines for Americans (DGA).

The challenge is how to produce the most healthful foods in a way that sustains employment in the agricultural sector and minimizes adverse impacts on the environment. All major constituencies concerned with food security and health must wrestle with sustainability and dietary choices together. It is right and proper for the DGA process to lead the way.

The commentary, which may be gated (sigh), grew out of a fall 2014 workshop initiated by the first author, Kathleen Merrigan, who was until 2013 the Deputy Secretary of Agriculture, and who now leads the sustainability program at George Washington University. Other authors include Tim Griffin, myself, Kim Robien, Jeanne Goldberg, and William Dietz. This issue also had been the focus of an earlier workshop, to which I contributed, for the Food Forum of the Institute of Medicine in 2013.

In an era of global climate change, the issue of sustainability is so important to the food system as a whole that policy-makers and the general public will inevitably find themselves considering environmental issues as part of almost any discussion of food choices. See for example the recent article in Nature by David Tilman and Michael Clark.

There is no way for the U.S. government to avoid having people talk about sustainability and dietary guidance jointly. That matter is already settled. The only question on the table is whether we will all need to struggle to compile multiple authoritative sources on these issues or instead whether -- as seems more sensible -- both issues will be addressed together in the same coherent federal guidance document.

Other countries include sustainability issues in their dietary guidance. For example, dietary guidelines in Brazil and the Netherlands take a comprehensive approach.

The U.S. Dietary Guidelines Advisory Committee (DGAC), whose report provides the scientific basis for the upcoming release of the 2015 Dietary Guidelines for Americans, already discusses sustainability in a sober and moderate way. It seems wise for the actual Dietary Guidelines to do likewise.

Unfortunately, some in Congress have taken steps to instruct federal agencies to limit the scope of the guidelines to "diet and nutrient intake" only. It would be absurd to limit guidelines to just those two topics. Along with preventing discussion of sustainability, the proposed language from Congress would prevent the guidelines from discussing physical activity. Yet, we all recognize that food and physical activity should be discussed together.

It is already within the mandate of the Dietary Guidelines to consider food security -- access by all people at all times to enough food. Far from being a loose cannon, the Dietary Guidelines Advisory Committee recognized environmental sustainability as sufficiently important to food security to deserve at least a brief and restrained mention. It would be silly to reverse that persuasive and sensible approach.