The publication every five years of the Dietary Guidelines for Americans customarily provokes heated debate, with different lobbies within the food industry, campaigners, academics and others putting forward their views on how they believe the US government should advise the nation about their diet.

So it has again proved while the 2015 Dietary Guidelines Advisory Committee (DGAC) has been preparing its report for the Department of Agriculture (USDA) and the Department of Health and Human Services (HHS), the two government agencies responsible for the guidelines.

Following a series of public meetings last autumn, a comment period closed at the end of December, and the DGAC will submit its report early this year, with the 2015 edition of the guidelines expected to be published in the autumn. 

There is intense debate sparked by the expectation the 2015 guidelines will include stronger advice to consumers than before to reduce consumption of foods containing added sugars, salt and saturated fat and may also no longer include lean meat as a constituent of a healthy diet.

However, a further, arguably defining, characteristic of the guidelines has also been much discussed, namely the possibility environmental criteria might now be included in what the US government advocates as a good diet. 

Some campaigners have been lobbying for this for many years but this time the DGAC has been considering the option seriously. In particular, it appears drawn by the idea that foods that would generally be viewed as healthier also tend to have lower environmental impacts. 

The DGAC food sustainability and safety working group noted that “a dietary pattern higher in plant-based foods, such as vegetables, fruits, whole grains, legumes, nuts and seeds, and lower in animal-based foods, is more health-promoting and is associated with lesser environmental impact than is the current average US diet”.

By that token, the possibility of environmental impacts being included would represent something of two-pronged threat to the meat industry, with meat-based protein being questioned both on health and environmental grounds.

The response from the meat production lobby was therefore understandably forthright. The North American Meat Institute (NAMI), the meat and poultry trade association formed this month by the merger of the American Meat Institute (AMI) and North American Meat Association (NAMA), said: “The Committee wrongly assumed if production animal agriculture were eliminated, the food supply as a whole would be more sustainable.” It said the DGAC appeared to be “acting on incomplete data”, citing a November 2014 paper in the American Journal of Clinical Nutrition that noted many analyses have focused on environmental impact per pound produced rather than per calorie supplied. When viewed in the latter manner, NAMI suggests, meat and poultry are “quite green”.

Those opposed to environmental criteria being included also stress it would lie beyond the statutory remit of the Dietary Guidelines. The DGAC’s focus on sustainability is “objectionable because it is not within the committee’s expertise”, NAMI said.

The National Cattlemen’s Beef Association (NCBA) also stressed environmental criteria lie beyond the DGAC’s purview. “Sustainability is not a consideration of the guidelines as set out by Congress,” a spokesperson for the NCBA, told just-food.

As appealing and logical as such a development of official dietary advice may appear to some, it is this factor which is likely to be most telling, and most probably means that environmental criteria will not feature in the 2015 guidelines.

Indeed, the DGAC has already received a warning shot on the issue from Congress. A directive within the recently passed Agriculture, Rural Development, Food and Drug Administration and Related Agencies Appropriations Bill 2015, stated: “The Committee [on Appropriations] is concerned that the advisory committee for the 2015 Dietary Guidelines for Americans is considering issues outside of the nutritional focus of the panel. Specifically, the advisory committee is showing an interest in incorporating sustainability, climate change and other environmental factors and production practices into their criteria for establishing the next dietary recommendations, which is clearly outside of the scope of the panel.

“The Committee directs the Secretary to ensure that the advisory committee focuses only on nutrient and dietary recommendations based upon sound nutrition science and not pursue an environmental agenda. Should environmental or production factors be included in the panel’s recommendations to USDA and the Department of Health and Human Services, the Committee expects the Secretary to reject their inclusion in the final 2015 Dietary Guidelines for Americans.”

Consumer advocacy group the Center for Science in the Public Interest (CSPI) conceded this early political intervention made the inclusion of environmental criteria “uncertain”.

As is so often the case, the fact political opposition will probably sound the death knell for this development should not be seen as a reflection of its validity. Simply because environmental criteria have not been part of the remit until now should not immediately disqualify this from the discussion. Arguably one of the key strengths of the Dietary Guidelines for Americans, first introduced in 1980, is that they are reviewed every five years by a panel of experts to take into account “the scientific and medical knowledge current at the time”. In other words, the guidelines are meant and expected to evolve.

It cannot be denied the emphasis since 1980 has been on health attributes. The USDA states the guidelines are intended to “provide the basis for federal food and nutrition policy and education initiatives” and “encourage Americans to focus on eating a healthful diet – one that focuses on foods and beverages that help achieve and maintain a healthy weight, promote health and prevent disease”.

What is viewed as constituting a “good” diet has changed considerably over the years, and substantially even within the lifespan of the guidelines, and rightly how the US government advises its people on what they should eat has taken account of this and will hopefully continue to do so. However, even more fundamental changes have been witnessed regarding what represents a sustainable diet, particularly in light of climate change and global food security.

The mooted inclusion of environmental sustainability within the Dietary Guidelines speaks not only to the growing importance being attached to environmental impacts and stewardship, but also to the inexorable convergence of human and environmental factors in how sustainability is viewed.

The logical consequence of this is that to be fit for purpose official dietary advice should take into account environmental impacts inherent in food production. This may well not happen with the 2015 edition of the Dietary Guidelines for Americans but it seems inconceivable that, as food security and climate change become ever more urgent and pressing considerations, official advice from governments will not increasingly focus on what constitutes both a healthy “and sustainable” diet, particularly given the apparent synergy between what is healthier for the individual and better for the planet.